The Chicken Mob Loot will drop 2 Raw Chicken Items when killed I found this issue when killing the chicken with a looting sword.
To find this issue
1 Enchant/Use a anvil to get the looting on a sword (It Happened With Diamond)
2 spawn a chicken in
3 Kill the chicken with the looting sword (I used looting 3)
hope this helps to fix this
and I don't know if this is a thing with looting
Screenshots soon