[accrual]

I imagine there are similar risks for eating one's hat as well, though perhaps a bit safer since it's not in contact with the ground and contains fewer materials.

So if you're going to make a bet and eat something if you lose - take the hat.

[beardyw]

Hatters stopped using mercuric nitrate in the last century, so you might be ok.

[john-h-k]

No way, I don’t buy it. If this is actually true I’ll eat my hat