If you aggro an enderman in survival, then switch to creative, it continues to teleport behind you.

Steps to produce:

1. Hit/aggro an Enderman in survival mode
2. Switch to creative mode
3. The Enderman stops attacking you
4. Walk away from the enderman
5. Notice the Enderman continues to teleport behind or near you (without attacking you) even if you try to run away from it.

Notes: It continues it even if you switch to spectator mode or back to survival.