I recently went through a similar incident with a new Arizona mountain king snake. She is now in a new enclosure , a tub with locking side handles. She was previously in a 10 gallon quarantine tank. I had clips on both ends of the tank. Probably should've had two more clips. One for each corner. Don't put him back there unless you add more clips or a different enclosure like a tub with locking handles.Good luck and I'm glad you found him.