Just had the Host Hat in greed mode and I was actually HEALED when I was hit by explosions (which carried an inferior run FAR further than I would've thought, until I reached Ultra Greed...). Since I had a few (though probably unrelated) items some confirmation is required. I was on a greed run with Magdalene and...just realized that I should've taken note of which items I had until that point.
Host enemy becoming host hat[edit source]
During greed mode arena battle, a bombed skull turned into a Host enemy. I had Samson run next to it and it jumped on top of his head, becoming a Host Hat. It appeared in the item list, and I'm sure I didn't have it before. Could not find this information elsewhere, and I want people to know. See if this option is hidden in the code. --Anon