Biskotti is a contestant in Animal Crossing: Chic Craze. She is listed third among the others.
There were many theories on her identity, but Biskotti is the sister of the famed Biskit.
The only reason "Biskotti" was in the show was because a friend of PC's, Lisa, was a huge Biskit fan and asked for the character to be put in. Since the contestants in ACS are always female, she asked for PC to somehow make it work, be it making a character that is Biskit's sister or just Biskit disguised as a girl. The latter was actually PC's original plan and Biskotti's "secret", but later she dropped the idea.
Biskotti's birthday is May 13, just like Biskit's.