Put the summary of the bug you're having here

What I expected to happen was...: I attacked an enderman (Singleplayer survival), in normal difficulty, and I expected it to teleport somewhere and attack me

What actually happened was...: It teleported away, and did not attack me

Steps to Reproduce:
1. Get an enderman to hold sand (The bug doesnt work if it doesnt hold sand or other blocks, i tested it in creative)
2. Attack it in singleplayer survival, normal difficulty.
3. It will teleport, but not attack you anymore