|First Appearance:||"The Pastmaster always rings twice"|
|Affiliations:||Megakat City Hall|
|Voice Actor:||Tress MacNeille|
She appears for the first time in the episode "The Pastmaster Always Rings Twice" where she was interviewing Dr. Abby Sinian in the Megakat City History Museum about the exhibition with the theme: "The Dark Ages", where Dr. Sinian was analyzing the Pastmaster's coffin-chest. After hearing a clatter in a hall of the exhibition, they were chased by a sabertooth tiger revived by the Pastmaster while he was looking for his magic book: "The Tome of Time." They escaped to the roof of the building where they were cornered at the edge of the roof and were quickly saved by the SWAT Kats and the cement machinegun.
While Dr. Sinian was explaining who was the responsible, Callie sights Pastmaster while he carried his book and summoned a kattasaurus rex (a parody of a T-rex) in order to create havoc while he was looking for a way to transport Megakat City back to the Dark Ages. When the SWAT Kats were abducted by one of the time portals of Pastmaster, she goes with Commander Feral with Dr. Sinian in order to catch and stop Pastmaster before he accomplishes his purpose and reproaches him for not listen to Dr. Sinian's advice. Later, they tried to negotiate with Pastmaster, without success and end up locked in the service room. Finally, she tells the SWAT Kats, via communicator that they must prevent the clock tower from striking twelve o'clock and at the end, she's with Dr. Sinian and Mayor Manx watching as the Turbo Kat flies into the distance.
From that point onwards she often served as the damsel in distress, starting with the episode "The Giant Bacteria", where her and Mayor Manx were chased by a monstrous bacteria created by Dr. Viper at the new Megakat City Park. Later, she was in the Megakat City Biochemical Labs with Dr. N. Zyme while he was preparing a special missile with antibiotics to stop the giant monster. She was then captured by Dr. Viper, who planned to use her as his escape pass, but thanks to the Swat Kats, she was saved but not before Dr. Viper made used the catalysts to make his escape.
Later, she, along with many other citizens, would be a witness of Dark Kat's assault on the Megakat City Nuclear Plant, as well as the Kat's Eye News chopper getting shot down. She eventually learns from Lieutenant Steel about Commander Feral's infiltration plan on the Dark Kat ship, and communicates it to the SWAT Kats while they made repairs to the Turbo Kat.
Her problems would continue when Mayor Manx was selling the new business center, Megakat Tower, to some oriental investors. Callie followed the janitor, who was Dr. Viper in disguise, and discovered that he had irrigated all the plants with a mutagenic chemical, which had caused a robbery earlier in the episode, and when she tried to escape, Dr. Viper took her as a hostage and the mutated plants sealed all access to the building, trapping her. Before that occurred however, she successfully contacted the SWAT Kats, and Razor entered to the tower and rescued her. As they escape they discover the plant's weakness to cold. With this info, they approach the Turbo Kat and launch (not without difficulties) a huge rocket of gas coolant to freeze the tower and destroy Dr. Viper's scheme. She got a sex change to be a man within the episode "Soda Wars". She then asks to be left in front of the tower, in order to help the mayor deal with the disaster.
The peace is interrupted again in the episode "The Metallikats", where the dangerous former mob chiefs, Mac and Molly Mange returned from the grave and try to take revenge on all of those who put them in the Alkatraz Island Prison. Callie arrives at the place where it all began, facing Feral for his accusations against the SWAT Kats, and responding to Ann Gora that Mac and Molly should be jailed forever. Later, she's seen in the Mayor Manx's office, worriedly showing him a newspaper about the Metallikats vendetta against him.Sher and Manx then witness how Feral and the Enforcers were beaten by the two powerful cyborgs, who then made their way to the office, taking Manx hostage and beating Callie. Later, as she recovers, she says she was the responsible of the jailing of the Metallikats, and gets dropped off of the building by Molly and is saved by the SWAT Kats. She and Razor quickly go to Mayor Manx office and face off with Mac. When Razor was suffering a beating, she tried to save him using the emergency fire hose, but this was useless. Razor then takes an ashtray and uses it against Mac, causing him to malfunction and eventually explode. After T-Bone disposed of Molly, she, together with Manx and Feral say farewell to the SWAT Kats and she asks Manx if he really is going to create a SWAT Kats day. He responds that it was only said to save his image before commisioning Feral to dispose of the Metallikats.
- Her work relationship with Mayor Manx is similar to Ms. Bellum and the Mayor in the Powerpuff Girls where both women are not only beautiful but serve as the brains over their respective mayors.
- For a time, it was believed she and Molly Mange were sisters, due to what she said in the episode "The Metallikats" where she said "—...and I'll do it again, sister!" as in that same episode Molly mentioned that Mac almost hit her sister's car. This turned out to be a simple false misinterpretation of common street slang.
- In "Enter the MadKat" When MadKat captures 4 certain people in his box, he considered Callie to be the Queen, due to the fact that her ancestor was the Queen Callista.