A feline litter usually consists of two to five kittens born after a gestation lasting between 64 and 67 days, with an average length of 66 days. Kittens emerge in a sac called the amnion, which is bitten off and eaten by the mother cat.
âHarley Quinn. Dr. Harleen Frances Quinzel, also known as Harley Quinn (a pun on the word harlequin), first appeared in the Batman: The Animated Series episode Joker's Favor, where she served as a humorous female sidekick to the Joker.
Then again, apparently, it was a tribute to Jack Nicholson and Alan Napier, according to the DC Wiki Article: Jack Napier is an alter-ego associated with the Joker. In Tim Burton's 1989 film Batman, it was used as the character's real name. This is a tribute to the actors Jack Nicholson and Alan Napier. Since then it has been used by several other incarnations of the Joker, although usually as an alias and not a secret identity.