/entitydata @e[type=Chicken] {IsChickenJockey:1b}
This command does not work if you execute it on a chicken. The chicken doesn't turn into a ChickenJockey.
MC-68437
Changing a Chicken to a ChickenJockey with /entitydata does not work
Resolved
Works As Intended
0
WAI
The Chicken is acting as a Chicken that would be a ChickenJockey, ther is technically no "ChickenJockey" entity since it's a Baby Zombie riding a chicken.