Midnight Private Eyes

Midnight Private Eyes is an American animated fantasy television series created by Dana Terrace for Cartoon Network. It was produced by Cartoon Network Studios and Flying Bark Productions.

Synopsis
The series follows Valerie Kipperson settling into her new apartment after graduating private detective school and ready for what comes next. What comes as a surprise to Valerie is that her new roommate is a vampire. The vampire, Cassius von Lovus-Shwarzius, is a mocking representation to his race, having replaced his taste for blood in favour of pizza and developed a tolerance to sunlight over the centuries. Strapped on cash after centuries of freeloading, Cassius reluctantly agrees to let Valerie turn their apartment into a detective agency for the supernatural creatures and cryptic entities seeking assistance when the sun sets on Toronto.

Main

 * Valerie "Val" Kipperson (Nicole Sullivan) - Fresh out of private detective school, Valerie is an eager to make a name of herself. She's full of imagination and enthusiasm, even more so upon learning that her town of Toronto has been housing monsters and other mythical creatures without her notice. Now serving as Cassius' partner in their apartment, she hopes to make the various clients cheerful with each night.
 * Cassius von Lovus Shwarzius (Vic Mignogna) - A vampire originally from 1800's Europe, Cassius is Valerie's roommate and partner. Cynical and lazy, he is secretly depressed over being separated from his beloved twin sister, Callista. Once a suave and charming individual, Cassius has now gotten overweight due to his newfound obsession with pizza and could no longer fit in his old velvet tuxedo. As the series progresses, he begins to warm up to Valerie after being put off by her energetic nature.
 * Tyler - Tyler is a curious merman who lives in a fountain near the apartment complex. Valerie befriends Tyler and teaches him human customs while getting swimming lessons in return. It's eventually revealed in season 3 that he is one of the lost royal heirs of Atlantis.
 * Holly - Holly is a pixie who unwittingly serves as the "secretary" to the Midnight Private Eyes. She was originally in the apartment long before the duo moved in, eventually working for them after starting their detective agency. While a helpful ally, Holly comes off as sarcastic and crass, mostly making fat jokes at Cassius' expense.