Put the summary of the bug you're having here
What I expected to happen was...:
Describe what you thought should happen here
When the horse spawns you should see it's full body.
What actually happened was...:
Describe what happened here
When spawned the horse's head and legs are only visible
Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ... Spawn the horse using the spawn egg.
3. ... You will then notice how the horse's main body is not visible
Your resource pack is outdated.