I am a sucker for slime toys and I bought a bunch of Gak in the 1990s. Sadly I was not the only one in my house who loved Gak. I left some Gak in a space reachable by the dogs and one of them went to town. The poor thing got so sick that they spewed vomit/Gack everywhere. After taking her to the vet where she was given a clean bill of health I spent 2 days trying to clean the stuff out of carpet with mixed success. It was so bad that in the room where it was most concentrated, we had to replace the carpet.
I never bought another container of Gak again.