Monster Kid

Monster Kid is a young monster who will stop at nothing to see their idol Undyne in action.

Appearance
Monster Kid is a yellow monster with no arms, a tail, and spines on the back of their head. They have markings under their eyes, presumed to be black eyes from them falling so often. One of the markings is bigger than the other. They wear a yellow shirt with brown stripes.

Personality
They look up to Undyne as a role model. They are an innocent monster who assumes the energetic attitude that pervades most of their actions. They seem to be a bit naive, as well as a bit clumsy, as they trip frequently. He also uses words like "c'mon", "dude", and "yo" frequently, usually considered childish ways of interaction.

Despite being notably frightened by the protagonist during the Genocide Route (once they discover the protagonist's intentions, at least), they stand up to the protagonist with an intense expression, ready to protect the Underground.

Neutral Route
Monster Kid first meets the protagonist in Snowdin. They note how both of them are wearing striped shirts, so they both must be children. However, Monster Kid does not seem to notice that the protagonist is a human child.

They later sneak out of Snowdin to explore the Waterfall, looking for Undyne. They follow the protagonist, not knowing that the latter is a human whom Undyne is searching for, and they feel a little jealous of all the attention that the protagonist receives. Monster Kid eventually finds out that the protagonist is a human, and reluctantly considers the protagonist an enemy. They try to say something mean to the human, in an attempt to become enemies, but feel bad for it and leave.

Just as the kid takes off, they trip over an edge and hang from it while Undyne approaches. The player is given a choice: After fighting Undyne, Monster Kid can be found in Snowdin. Depending on the protagonist actions, they will either resent or idolize the protagonist.
 * Help them climb up the ledge:
 * Monster Kid defends the protagonist from Undyne, who backs off. They decide that they'll remain friends with the protagonist and leave for home.
 * Let them fall:
 * Undyne dives down after Monster Kid to save them—she is badly hurt but refuses to rest. They then tell Undyne that she was right about the human, who just stood there waiting for them to fall. This makes Monster Kid hate the protagonist and all humans.
 * Run to Undyne:
 * Undyne saves Monster Kid and is badly hurt. They will tell Undyne that she was right about the human, who was too eager to fight her to bother saving them. This will also make Monster Kid hate the protagonist and all humans.
 * Run away from Undyne:
 * Undyne helps Monster Kid up, who tells her that the protagonist was just going to get help from others.

True Pacifist Route
They are seen cheering the human onto victory as they face off against Flowey. In the epilogue, they say they don't think Undyne is that great anymore; and that they found themself a new idol (This can either be (presumably) Papyrus, or the protagonist). Monster Kid is also seen during the credits, attending Toriel's school.

Genocide Route
Despite being warned by Undyne that the protagonist has hurt a lot of people, Monster Kid approaches the protagonist anyway, in disbelief. The protagonist turns away, and as Monster Kid questions the protagonist about not answering them, the protagonist silently approaches Monster Kid aggressively with a "weird expression". Monster Kid begins to panic and wonder what they could do, and then stands up to the protagonist out of desperation, stating that if the protagonist wants to continue to hurt others, the protagonist would have to go through them, and the protagonist eagerly enters a battle with them. The protagonist then declares that the kid is "in [the protagonist's] way". After subsequent resets, the protagonist simply attempts to trick the child into turning the other way but fails and re-engages battle. This encounter cannot be escaped from. A slowed down version of "Anticipation" is played during the "battle".
 * If Monster Kid is attacked, Undyne takes the blow in their place. The kid will escape, whilst harboring a shocked expression. They are not seen again in the rest of the game; it is assumed they evacuated with the others.
 * If Monster Kid is spared, they will say they knew the protagonist wasn't that bad and leave. This aborts the Genocide Route.

Quotes

 * Yo! You're a kid too, right? I can tell 'cause you're wearing a striped shirt. [1st encounter]
 * Yo, everyone ran away and hid somewhere. Man, adults can be so dumb sometimes, haha... Don't they know we've got Undyne to protect us!? [Genocide exclusive]
 * Yo! Are you Sneaking out to see her, too? Awesome... she's the coolest right!? I wanna be just like her when I grow up... Hey, don't tell my parents I'm here. Ha ha. [2nd encounter]
 * Yo... did you see the way she was staring at you...? That... ... was AWESOME! I'm SOOOO jealous! What'd you do to get her attention...? Ha ha. C'mon! Let's go watch her beat up some bad guys! [3rd encounter]
 * Yo... did you see that!? Undyne just... ... TOUCHED ME! I'm never washing my face ever again...! Man, are you unlucky. If you were standing just a LITTLE bit to the left...! Yo, don't worry! I'm sure we'll see her again! [4th encounter]
 * Yo! [5th encounter]
 * Yo, you got an umbrella? Awesome! [1st encounter with an umbrella in hand]
 * Yo... Where's the umbrella...? Ha... ha... [2rd/3rd encounter if the protagonist once had an umbrella, but put it back]
 * Yo... [3rd/4th encounter onward if the protagonist are currently with/without an umbrella in hand]
 * You can't hold an umbrella either? If you're walking anyway, I guess I'll go with you, haha... [1st encounter without an umbrella in hand]
 * Yo! You got us an umbrella? You're the best! (2nd encounter with an umbrella in hand)
 * Yo! Ready yet? [2nd/3rd onward with/without an umbrella in hand]
 * Let's go! [Continuation]
 * Yo, I already looked, Undyne's not over here. So I guess I'll see ya later, haha. [if the protagonist goes left to the umbrella room]
 * See ya later! [if the protagonist goes left again onward]
 * Man, Undyne is sooooooo cool. She beats up bad guys and NEVER loses. If I was a human, I would wet the bed every night... ... knowing she was gonna beat me up! Ha ha. [1st monologue]
 * So, one time. We had a school project where we had to take care of a flower. The king - we had to call him "Mr. Dreemurr" - volunteered to donate his own flowers. He ended up coming to school and teaching the class about responsibility and stuff. That got me thinking... YO! How COOL would it be if UNDYNE came to school!? She could beat up ALL the teachers!! Ummm, maybe she wouldn't beat up the teachers... She's too cool to ever hurt an innocent person! [2nd monologue]
 * Yo, this ledge is way too steep... [monster kid at the ledge]
 * Hmm... [Talk to Monster Kid before heading left]
 * Hmm... Yo, you wanna see Undyne, right...? [if talked to/if the protagonist heads left]
 * Put up your umbrella and climb on my shoulders. [Leaving with umbrella in hand]
 * Yo, you aren't going to be able to climb with an umbrella. [Talked to again with an umbrella in hand]
 * Climb on my shoulders. [if the protagonist goes left]
 * Yo, you go on ahead. Don't worry about me. I always find a way to get through! [Monster Kid after the protagonist climbs the ledge]
 * Undyne!!! I'll help you fight!!! YO!!! You did it!!! Undyne is RIGHT in front of you!!! You've got front row seats to her fight!!! ... Wait. Who's she fighting??? H-hey! You aren't gonna tell my parents about this, are you? [6th encounter]
 * Yo! [Introduction]
 * Yo, I know I'm not supposed to be here, but... I wanna ask you something. ... Man, I've never had to ask anyone this before... Umm... Yo... You're human, right? Haha. Man! I knew it! ... well, I know it now, I mean... Undyne told me, um, "stay away from that human." So, like, ummm... I guess that makes us enemies or something. But I kinda stink at that, haha. Yo, say something mean so I can hate you? Please? [7th encounter]
 * Huh...? Yo, that's your idea of something mean? My sister says that to me ALL THE TIME! Guess I have to do it, haha. [Yes]
 * Yo, what? so I have to do it? Here goes nothing... [No]
 * Yo, I... I hate your guts. ... Man, I... I'm such a turd. I'm... I'm gonna go home now. Yo, w-w-wait! Help! I tripped!
 * Undyne... You... You saved me! Huh, They ran away? Yo, you're wrong... They went to get help! They'll be back at any second!! O-okay, I'll go home... [Protagonist heads to right; Undyne will jump off after Monster Kid]
 * Wh-what are you standing around for? get over here, dude! [Protagonist does nothing]
 * I... I'm slipping! [Monster Kid will fall, and Undyne will jump after them] Undyne... you saved me...? Yo, I thought I was a goner, haha... ... wait, are you okay? It looks like you fell pretty hard... Th-this is my fault. I should have stayed away from them, like you said. [Protagonist continues to do nothing]
 * They just went straight to fight you instead of helping me... I was so scared, and you... What? You're gonna go fight them now? But you look hurt... You should rest, haha... ... W-warriors don't rest huh? Undyne... you're really cool. [Protagonist rushes toward Undyne; Undyne will jump off after Monster Kid]
 * They just stood there... Watching... Waiting for me to fall. [Protagonist did nothing]
 * Y... y... yo... dude... If... if y-you wanna hurt my friend... You're gonna have to get through me, first. She's gone... Yo, you really saved my skin. Guess being enemies was just a nice thought, haha. We'll just have to be friends instead. ... man, I should REALLY go home... I bet my parents are worried sick about me! Later, dude! [Protagonist saves Monster Kid]

Genocide Route

 * Yo! [Introduction]
 * 'Yo. Undyne told me to stay away from you. She said you... You hurt a lot of people. ... But, yo, that's not true, right!? ... ... yo... Why won't you answer me? A... a... and what's with that weird expression...? Oh... Oh man... (Man, my h-heart's pounding right out of my chest...) (... what would Undyne do?) (...) Yo... Y-you'd b-better st-stop r-right where you are... Cause if you w-wanna hurt anyone else... you're... You're gonna have to get through me, first. A... an... and... (Engage battle)
 * S-see? I knew y-you weren't so bad! I've gotta go tell Undyne she was wrong about you! [Protagonist spares Monster Kid]
 * Undyne... You're... You're hurt...  [Protagonist attacks Monster Kid; Undyne will arrive and take the blow]
 * [Undyne] Hurt? It's nothing. Next time, listen when I tell you to leave, okay?
 * [Monster Kid] Undyne... I...
 * [Undyne] I'll take care of this! Get out of here! [Monster Kid will leave]

True Pacifist Ending Epilogue

 * Yo... There you are!
 * I've been kinda worried about you since you ran away. ... But now i'm just kinda mad, ha ha. If Undyne hadn't saved me, that woulda been bad... [If the protagonist ran away from Undyne during bridge sequence]
 * ... [Talked to again]
 * I've been kinda, doing some thinking... Maybe Undyne... Isn't actually as cool as we thought. She's just kinda... mean. But YO!!! I just found out about someone WAYYY cooler!!! Nyeh heh heh!!! [If protagonist saved Monster Kid during bridge sequence]
 * Nyeh heh heh, dude. [Talked to again]

Flavor Text

 * Looks like free EXP. [Check]
 * Monster Kid quivers anxiously. [Neutral]
 * In my way. [Encounter]

Trivia
Monster Kid
 * was designed by Magnolia Porter, creator of Monster Pulse. She also designed Snowdrake, Ice Cap, Jerry, and helped design Gyftrot.
 * Monster Kid's design may have been inspired by the Pokémon Scraggy; both are small, yellow, bipedal lizard-like creatures with protruding teeth. While Scraggy may have arms, it has to perpetually use them to hold up its pelt—which is a lot like not having arms at all, just like Monster Kid.
 * Monster Kid is the only monster that cannot be defeated in battle.
 * In Waterfall, one can follow the conversation of someone and their sister via Echo Flowers. These may be Monster Kid and their sister.
 * When walking in the rain with Monster Kid without holding an umbrella, the protagonist's reflection will glitch and not animate correctly.
 * Going back to the room with the umbrella bin will make them say "Yo, I already looked, Undyne's not over here".
 * Monster Kid's assumption that the protagonist is a kid because of their striped shirt is a reference to the MOTHER series, where all of the protagonists are kids who wear striped shirts.