Things that block Changeling attacks but probably shouldn't

[Kovirii]

Give the changeling a de-fat sting. There you go.

Hire C.H. Ling for all your liposuction needs! Watch the fat drain away!

I vote we give the changeling a more powerful sting that turns your insides into soup, the caveat being that for it to happen you have to be aggressively grabbed, or naked.

In reality, poking someone with your proboscis and not draining them (whether by choice or interruption) would leave some lipolicide, acid, or anticoagulant in them from the "injection".