Which Witch? by Eva Ibbotson
My rating: 3 of 5 stars
Kindly white witch Beladonna has never been able to do black magic, but when the handsome wizard Arriman sets a contest to find the wickedest witch to be his bride, she is determined to give it her best shot.
Beladonna has her work cut out for her if she wants to shake her embarrassing affinity for begonias and cute woodland creatures, but she is helped out in the contest by an orphan named Terence Mugg. Terence owns a pink earthworm named Rover, and Rover seems to be just the familiar to help Beladonna accomplish the necessary nastiness.
The good witch's competition is her own coven - and each witch is icky in her own way, accompanied by a familiar (none of the black cat variety, but far more ingeniously odd). The contest is inventive and sometimes even scary: Madame Olympia's hideous Symphony of Death is a stomach-turning trick that H. P. Lovecraft would have been proud to write.
The side characters are as fun as the witches - I particularly liked Mr. Leadbetter, Arriman's tailed but rather ordinary secretary, who enjoys watching Miss Universe competitions. There is also Arriman's silent friend, a creepy wife-killer ghost named Sir Simon: Sir Simon's fate is amusing and appropriate (actually, if Ibbotson had written a sequel about that relationship I would read it in a heartbeat).
Ibbotson's witches possess a Charles Addams type of evil (you may want to check out The Addams Family: Evilution if you're a fan of macabre humor). They have an affinity for creepy-crawly things but doing little actual harm to innocent strangers - with the exception of the truly wicked Madame Olympia, whose evil is just a tad too evil for everyone's taste. If you want real wickedness, you'll have to turn to Roald Dahl's The Witches.