Children's book about a green monster that hatches from and egg

[elw123]

I've asked everyone and I'm starting to feel like I imagined this book. It would have been written about the 80's. It's a children's book about a creature that hatches from and egg and looks like a floppy dragon. I think his name was thing but I'm not sure about that. I loved the book but now no-one else remembers it existed!
Help!!