After I moved house a couple of years ago, several odd little books that had slipped behind others on the shelves, or got stuffed into odd corners, revealed themselves, and needless to say, they're still lying about my new house 'unputaway' now.
From somewhere or other I picked up three Will O' The Wisp books by Nicholas Spargo. They're dated 1981 but I'm sure I bought them at least a decade after that. As well as one of the covers, I thought you might enjoy the picture of the Moog transforming into a werewolf after accidentally drinking one of Evil Edna's potions.
The Moog was my favourite. "I think that I am a doggie..."