We sang (in primary (mid 70s to early 80s):
Yellow belly custard
Green snot pie
All mixed together with a dead dog's eye.
Slap it on a butty,
Nice and thick,
Wash it all down with a cup of cold sick.
Utterly minging, I know. 🤮 We were such foul wee buggers. 😅
Were there any other horrors doing the rounds at your school(s)? No mean/nasty stuff please. 🙂