Thank you! - I loved it. And your diligence inspired me to look for the other words . . .The song has been playing in my head since I saw your comment, thank you for the earworm
The main bit that plays over and over is "Don't you open that trapdoor! 'Cos there's something down there.. *80s music" My memory is terrible and it was a long time ago, so the rest of the words eluded me too, had to look it up to refresh my memory I'd forgotten just how 80s it sounded, but it's still awesome!
"Creepy, crawly, slimy things, that stick onto your skin... Horrid beasts with tentacles, that want to pull you in... Squirmy worms, slugs and snails, that lie there in a goo... They'll wait down there forever, 'till they get their hands on you... Stay away from that trapdoor, 'Cos there's something down there..."