Llama has incorrect hitbox unless it is reloaded

The bug

Llamas have an incorrectly sized hitbox until they are reloaded.
It looks like they might have the horse hitbox (not as tall as llamas but wider).

Steps for reproducing (via spawn egg])

Suffocation damage

1. Spawn in a llama in a 1x1 hole with solid blocks as the walls
2. Observe that it suffocates, although a llama is 1x1 and should fit in the space

Block collision

1. Spawn in a llama and try to push it against a wall (nudging/piston/water)
2. The llama cannot be fully pushed against the wall