Altar Self

You assume a different form. When you cast this spell you become an altar. While in this form, if a creature is slaughtered on you, regain 1d6 hit points for each size category, starting at 1d6 for a tiny creature. A tiny creature provides 1d6, a small creature provides 2d6, a medium creature provides 3d6, and so on. You can choose to end the spell and revert to your normal form as an action at any time before the spell ends.