Mister Featherly is a chicken actor who first appeared in Situation: Comedy under the name Philo Pennyworth.
Sam & Max first meet Philo Pennyworth during Situation: Comedy, where he plays the role of Mr. Featherly in the hit series Midtown Cowboys. At the time, he finds it very annoying when Sam and Max call him by his character's name. Ironically, though, by the time they meet him again in Night of the Raving Dead he has changed his legal name to Mister Featherly to make his contracts easier (and gets annoyed when called Pennyworth).
In Chariots of the Dogs he is revealed to be present at the beginning of the universe, thereby being The Chicken. However, Sam and Max then take him away and replace him with an egg, thereby making it The Egg. It is later revealed that the egg in question is somehow laid by Featherly himself.
In What's new, Beelzebub?, he is seen at Abes Bachelor Party wearing only a scarf.
Mr. Featherly returns in The City That Dares Not Sleep to aid in Sam's effort to restore Max to normal, but refuses to be eaten along with the team due to union rules and hating to be eaten at all. He reluctantly gives Sam an egg to help in his giant corn dog, though not without some aid in privacy.