omg what do you have in your mouth?

I decided to start a mommy blog after an incident that happened today. I have a 7 month old boy who started to crawl really well about a week ago. Obviously my days of propping my son in front of Sesame Street while I do whatever I need to do are over. Today I set him down (right in front of me, I swear) and sat on the couch to check my email. In the corner of my eye I see him bring his hand to his mouth. I didn't really think about it until I actually looked over and see him playing with something in his hands. Upon closer inspection I realize it's cat vomit.
Yes. There is my son happily indulging in tasting and smearing cat vomit all over himself. I jump up and I'm yelling "no no no" and when I pick him up and start wiping the vomit off him and his face, he has a total meltdown.
"ROAR! Whyyyyyy are you taking me away from the cat vomit????" (similar type meltdowns have included: why are you taking me away from the electrical outlet? why are you taking me away from the fireplace? why can't I go inside the litter box? why can't I eat the tube of Lotrimin? why can't I grab my scrotum that is covered in poop while mommy changes my diaper? etc, etc.)
So for Christmas I have asked for Grandpa to buy us an octagon play pen.

I am wondering what is the worst thing other parents have seen their child eating??