Two chickens fly around the screen and drop eggs.
Fight starts with 2 Infinity Chickens rotating around the screen with an Instant Laser connecting them. When you destroy one Infinity Chicken, the other one flies around the screen and shoots at you.
For more information about a list of all bosses, please go here: Chicken Invaders 4: Ultimate Omelette: Bosses.
Chicken Invaders: Revenge of the Yolk Christmas Edition
The Twins are dressed up like Santa.
Chicken Invaders: Ultimate Omelette Christmas Edition
The Twins look like they are made out of chocolate.