Some addon mobs can crash the game

When I spawn some addon mobs the game will crash

Steps to reproduce:

1. Download/create an addon
2. The addon is successfully imported
3. Be sure to see if there are any mobs in this addon
4. Create a new world
5. Be sure to use this addon you made/downloaded
6. Wait until it loads
7. Spawn a mob from the addon and do some actions that are used for this mob
8. The game crashes