Just to complete Valorum's answer
In Superman v1 #335 (1979) we can find Miss Bgbznz
Superman v1 #335 (1979)
Yes, strange are the ways of love... And stranger still... In a strange land...
Priest: ... I now pronounce you imp and wife!
Bgbznz: Oh, Mxy, darling... I know how much you love a good joke-- giggle So here's one you'll adore! I figured you'd never marry me if you saw what I really looked like... ...So I magically projected the image of me you proposed to! But now that we're hitched-- I can show you my real self: this!
Mxyzptlk: Yaaaah! Now... That's not funny!
Someone from the crowd: Mxyzptlk may have attoned for his misdeeds-- But he still hasn't learned what's funny and what's isn't! -- Or else he'd appreciate the fact that his wife's joke is... a veritable work of art! Ha ha ha!
Close-up
Her more-human-like form was a trick for luring Mxyzptlk. According to her profile they got divorced later.
