Endogeny

Endogeny is an amalgamate, and the first amalgamate to be introduced as such. It's composed of the Determination-filled souls of several [presumably five, judging by the silhouettes of the dogs in its limbs] dog monsters, including the parents of Dogamy and Dogaressa and other miscellaneous family members of Doggo, Greater Dog, and Lesser Dog.

It exudes a fluid from its single orifice, which becomes a happiness froth when the Endogeny is excited. The silhouettes between its legs gain faces after it is spared.

The name Endogeny comes from the word endogenous, which means "having an internal cause or origin" and refers to the the amalgamate containing multiple members of a single family (and possibly hinting at it containing the parents of some of its own components)

Attacks

 * A sprite resembling the Annoying Dog [but with the Endogeny's signature orifice for a face] retracts its legs and reveals a rocket underneath its tail, using it to fly towards the SOUL in a straight line several times before the attack ends. This attack is capable of exiting the boundaries of the battle square.
 * The dog appears to the right of the screen, first faceless but then developing the orifice. Then it stretches its legs, moving up and down while firing arrows towards the SOUL in a random pattern.

Strategy

 * You can spare Endogeny by beckoning, petting, playing and then petting again twice.
 * The Hush Puppy can be used to pacify and spare the Endogeny immediately, as can the Stick [in similar fashion to other dog monsters].

Endings

 * At the end of the Pacifist Route it can be seen with most of the other dog characters, revealed to be its family, outside the Snowdin Library. When interacted with it imitates the signature sound and [perhaps weakly] facial expression of Greater Dog, who probably inherited these traits from Endogeny. Its yellow text in the credits lists it, along with the other amalgamates, as living with its family, implying it continued to spend its time with the other dogs.

Flavor Text

 * Amalgamate is watching you intently. [Neutral]
 * It smells like a bunch of dogs. [Neutral]
 * It's unclear how many dogs this counts as. [Check]
 * You try looking away, but it seems to appear everywhere you look. [Ignore]
 * It's the Amalgamate. [Encounter]
 * You call the Amalgamate. It bounds towards you, flecking a strange liquid from an orifice. [Beckon]
 * Amalgamate is hovering close, looking for affection. [After Beckon]
 * You pet the Amalgamate. It convulses rapidly... then calms down. It rests quietly on your lap for a moment... Zzzzz... Suddenly, it shoots away and crawls wildly on the walls! [Pet]
 * Amalgamate is striking the wall with its claws. [after Pet]
 * You throw your weapon into the corner of the room. The Amalgamate brings it back to you... Proudly? You repeat this process a few times. Now Amalgamate is very tired... It leans its dripping, amorphous body on you... [Play]
 * Amalgamate is twitching affectionately. [after Play]
 * You pet the Amalgamate. It starts to generate a Stage I Happiness Froth. [Pet]
 * Amalgamate's convulsions intensify. [after Pet]
 * You pet decisively. The Amalgamate seems to be satisfied by all this. [Pet]
 * Endogeny is contented. [Meeting Spare conditions]
 * You'd give it a tummy rub, but it's not clear where its tummy begins or ends. [Petting after meeting Spare conditions]
 * Amalgamate seems too tired to play. [Playing after meeting Spare conditions]
 * The Amalgamate's feelers rotate quickly. Nothing else happens. [Beckon after meeting Spare conditions]

Trivia

 * Like all other dog characters in its family, Endogeny contains the word dog within its name.
 * The nature of one of its attacks combined with its being described as able to fly away towards walls might suggest it possesses some form of propulsion on its body, like a rocket.
 * A comment by Toby Fox on the Steam Store page says, “If you play this game can you count the dogs for me? I'm not very good at it.” This may be a reference to Endogeny, whose Check text says, “It's unclear how many dogs this counts as.”
 * The sequence of actions required to spare Endogeny is the same as for Greater Dog.