Jason Heller is the youngest son of Mordecai Heller and Jenni Graves.

Appearance:
Jason is a white, black-footed cat with blue eyes with a black spot on his chest, over his heart. He doesn't wear glasses but his eyes are sensitive to light.

Childhood:
Jason was born March 30th, 1930. As a baby, Jason was very wild and caused a lot of fuss over everything. He loved being destructive and was also stubborn when he didn't get what he wanted. His father and brother wanted nothing to do with him and often ignored and neglected him. His mother and sisters mainly took care of him. Jason was saddened he didn't have a good relationship with his father or brother and tried drawing pictures and making things for them to make them proud of him but to no avail.

Jason began school alongside his brother and sisters at the age of 5. Jason was always the one who got into trouble both at school and at home. He often got bullied and had to be rescued by his brother. Jason couldn't even make it through kindergarten without getting into trouble. Fortunately, his mother and sisters teach him to control himself. Jason develops a mind for science and math, finally able to impress his father and brother.

Time at Lackadaisy:
When he turned 13, Jason is allowed to come into Lackadaisy. He is named the heir to Marigold and the Graves Family fortune.

Personality:
Jason is very hyperactive and optimistic. He enjoys things that explode and make loud noises like fireworks. He loves roasting marshmallows and sweet things. He is also a friendly and caring individual. He is also easily forgiving and doesn't hold grudges.

Jason is also a highly curious individual. He is also quite cowardly, showing fear when he accidentally breaks Justin's favorite toy, the latter shows him to the ground in anger and Jason runs away in tears, though this was out of sadness for breaking his brother's toy and thinking he hated him.

Despite being a wild card, Jason learns to calm himself through using his energy to dance and in science experiments.

Abilities:
Jason is highly skilled in explosives and has a high tolerance for pain.
He's also extremely acrobatic and agile.
Jason is skilled in cooking and gardening.
Jason is also a skilled musician, enjoying drums.

Trivia:
Jason's full name is Jason Bruce Heller, getting his middle name from his maternal grandfather.
Jason's favorite drink is tea.
Jason's birthmark on his chest is meant to symbolize Mordecai's satanic mark on his chest as they are both in the same area on their chests, over their hearts.