Polymorph spell allows players to "revive" and re-loot dead bodies

[Mieekaserra]

Describe the bug

When using the spell polymorph on a dead body, then use it again on the chicken, the body respawns with a additional loot set.

To Reproduce

Steps to reproduce the behavior:
When casting Polymorph on a dead body, it will turn into a living chicken.
When casting polymorph again on the chicken, it will revert to the dead body from before - but with all loot replenished

Expected behavior

Spell shouldn't work on corpses IMO.

[ProbablyManuel]

Fixed in #281