Zombie Chickens are common enemies found in many Rayman games. In the Rayman Origins manual, it explains that Betilla and the Nymphs lost a sack of Lums due to chasing these crazy chickens over a cliff. That might've been what caused Rayman to be born with no limbs.
When the Robo-Pirates arrived, the hens were so terrified they laid eggs which contained Zombie Chickens.
The Chickens are introduced in this game. They are common and easy to defeat, requiring only a shot from one of Rayman's fists. In this game, they only appear in swampy levels. Zombie Chickens appear in The Marshes of Awakening, The Bayou, The Cave of Bad Dreams, The Sanctuary of Rock and Lava (Beneath the Sanctuary of Rock and Lava in Rayman 2: Revolution), and Tomb of the Ancients.
Most of the time, the Zombie Chickens attack while Rayman is rafting on a barrel over dangerous water and swarm in as an attempt to knock him off the barrel and into the water. If Rayman is knocked off, it will cause Rayman to die.
The Chickens return in this game as ghost-like creatures. In Rayman 3, they are called Scowlers. They reside only in the Desert of the Knaaren. They appear to slow Rayman down while he is carrying eggs, and he can defeat them with a simple punch. Scowlers often come in waves. They have special theme music in this game.