Swimmer Guy is a character who appears "The First Guy To Ever Swim", the 21st episode of The First Guy. He is the first person to ever swim in an ocean.
TFG20 - The First Guy To Ever Swim
Swimmer Guy decided to jump in and float in the top layer some drinking stuff for no reason. He stayed there for a while, until triangle-tailed fish came and made the drinking stuff red and taste like pennies.