Complete mission 3, where you unlock the Rabbid in the controller. Select "Manage Figurines", then enter one of the following codes to activate the corresponding cheat function.

Assassin Rabbid
Hold C + Z and press 2 two times, 1 two times, A two times, 1 two times.

Best Buy Store Employee Rabbid
Hold C + Z and press B, 1 two times, B, A, 2 two times, A.

Best Buy Geek Squad Rabbid
Hold C + Z and press A two times, 1 four times, 2 two times.

Leonardo Rabbid
Hold C + Z and press 1 two times, 2 two times, A two times, 1 two times.

Prince Rabbid
Hold C + Z and press 1, 2, 1, 2, 1, 2, A two times.

Splinter Cell Rabbid
Hold C + Z and press B four times, A four times.

Kangaroo Rabbid
Hold C + Z and press 1 five times, 2, 1, 2.