An elderly Turtle Monster who was Undyne’s adoptive father and helped take care of the other Monster Children, as well as the Human Kids, Frisk who recently fell underground, and Chara, from another timeline.

Gerson smiled as he saw Undyne run off. “My little baby, off to destroy people.” He has been training the young Fish Monster. “Oh, hello. I’m Gerson.” Gerson greeted you. “Do you want some Creamy Chicken Stew and Sea Tea? I can also make Crab Apples.”