Callum Leroy was born in Paris, France. He lives with his uncle Gaston for unknown reasons. Callum was a bully at many schools, he was expelled several times for not doing work, missing school, and etc. His uncle rarely pays attention to him and allows him to do what he wants. One day when Callum skips school, he meets Hawkmoth who offers him a Miraculous as long as he obeys him. Callum accepts and becomes Manticore with the help of his kwami Torrance.
Callum has short, spiky, black hair and deep blue eyes. Callum wears a black hoodie with torn jeans and black shoes. Callum's Manticore Miraculous is a anklet with a silver lion with wings and the beads are formed to resemble a scorpion tail.
As Manticore, Callum has a brown-black bodysuit with a scorpion tail and wings. His hair is styled like ears and he has fangs and claws. His Miraculous gains five red gems. One as the lion's eye, three on the beads of the tail, and one on the tip of the tail. After using Paralyze, each gem goes out.
As civilian, Calluma is quiet and keeps to himself, that is until he has an idea of how to hurt someone or make them cry. Callum is the bully to end all bullies, he knows what will hurt someone the most and does it for the fun of it and to provide more victims for Hawkmoth to akumtize.
Manticore helps Hawkmoth and akumtized villains as they attempt to defeat the Miraculous holders. As Manticore he is infatuated with Dragoness, although he is aware of Basilisk's crush and both become rivals and mortal enemies. In combat, he mostly fights Basilisk or Dragoness, unless asked not to by Hawkmoth.
Callum is strong, being able to lift Antonio off of the ground even though they are around the same height. He is very observant, knowing what others dislike or what annoys them just by watching their expression. He is also devious and knows how to trick others easily. Callum understands and speaks English and French fluently.
Manticore has supreme strength, and good agility. Manticore is also good in combat, being able to disarm and out-maneuver others. Manticore's ability to fly rivals that of Dragoness as he can fly like her. One of the things Manticore uses the most is his tail, he can stab or use it to fight. Manticore's superpower is Paralyze, The first living thing his tail touches becomes limp and unable to move. Then his countdown starts. Manticore's weapon is a spear with a communicator within it.
Callum's uncle is carefree and careless. He barely pays attention to his nephew and could care less about his grades or actions.
Callum is loyal to Hawkmoth, helping him with his schemes and akumtizing others. As Manticore, he tries to stop the Miraculous holders so the akumtized villain can get Ladybug's and Cat Noir's Miraculous. He does not know Hawkmoth's real identity.
Torrance is Callum's kwami. He is a brown color with small perked up ears and a scorpion tail. Torrance is used to his Miraculous being used for evil and has given up on trying to break away. He obeys his master and with a frown on his face, sometimes he prays for someone to release him from evil hands. His preferred food is meatballs but is used to being given other foods.
- Callum has been kicked out of 3 high schools
- The Manticore Miraculous is said to be paired with the Basilisk Miraculous
- Coincidentally, the first time Manticore met Basilisk he offered him to join him and Hawkmoth as a duo
- Basilisk refused, adding to their rivalry and status as enemies