Steps to reproduce:

1. Spawn a creeper and summon a lightning on it to create a charged creeper;
2. Lock a bunch of zombies, skeletons, wither skeletons, creepers, etc with the creeper;
3. Use a flint and steel to make the creeper explode.

Expected results:
Only one mob drops the mob head.

Observed results:
Every mob that has been killed drops the head.