Wungle's suggests that some body parts of the target get a life. That is to say it animates a part (the spleen) of a target's body, causing it to leave the body and become a spleen runner which travels around, eventually returning to the body if that body is still around. The runner can be killed, and to do so will leave a spleen on the ground.

Understandably, the target isn't too happy with the results of the spell, and will attack you in response. The effect of losing their spleen is to make the target less healthy than normal. The target returns to normal after their spleen returns. Naturally, the hp will also return after a period even if the spleen runner is caught and killed.

 

Effectively, this spell reduces the maximum hp of the victim for a while.