Very little is known about Ken Shiga. Apparently born with his superhuman abilities, he became a costumed crime-fighter with his friend Chipmunk Hunk when both began attending Empire State University.
Koi Boi was created by Ryan North and Erica Henderson. He made his first appearance in The Unbeatable Squirrel Girl #2.
Major Story Arcs
Koi Boi meets and becomes friends with fellow crime-fighter and computer sciences student Squirrel Girl while both are attempting to defeat Hippo. During Ratatoskr's attempt to take over the world he and the other heroes join forces to try to take her down. In the attempt he is corrupted by Ratatoskr, and briefly joins her army of brainwashed humans before she is ultimately defeated. He later helps Squirrel Girl defeat Swarm.
Powers and Abilities
Koi Boi is able to communicate with fish; the limits of this ability are unknown. He is also able to swim at superhuman speeds and to breathe underwater. He is able to grow very slowly to fit the size of his container. He has magnetic cells similar to some fish, which give him the ability to navigate using Earth's magnetic fields. Due to his powers he has developed advanced knowledge of fish and the fish-adjacent.