Willo the wisp was a children’s cartoon series on British TV in 1981, repeated in the late ’80s (which is when I remember seeing it). The narration and all the voices were done by the glorious Kenneth Williams. (I don’t know about other countries, but the UK has a strange habit of getting spectacularly notable people to do voice-acting on programmes aimed at children far too young to be remotely impressed. See also Willie Rushton on The trap door, David Jason on Danger Mouse, Ringo Starr on Thomas the tank engine, and most recently Sir Derek Jacobi on In the night garden….)
Cruel fate has it that only three episodes appear to be known to the internet, at least as far as my limited powers of googling can discover. The other two are The dragon and The thoughts of Moog. I am given to understand that a new series was made recently, obviously not involving the late Kenneth Williams and changing Evil Edna to a flat-screen television and making Mavis less fat. Needless to say, I refuse to sully my eyes with any such abomination.