Board Thread:General Discussion/@comment-27836448-20160220210617/@comment-27907368-20160303094629

MysteryMan probably isn't Gaster's sprite. Now that it officially occurs in the game without alteration, I am more convinced of this.

The sprite we see for the [REDACTED] room (written in wing dings) is probably it. Here is a picture "in game".

MysterMan is a reference to Uboa and could be referred to by the riverguyboatman as the man from the other world, whereas Gaster is the man who talks in hands.