Think your cat’s big? Not compared with Fenrir. Fenrir is 18.83 inches (47.83 centimeters) tall, and the Guinness Book of World Records has named him the world’s tallest living domestic cat.

His name, Fenrir, comes from one of Saturn’s moons, Guinness said, but like most cats, he has plenty of family nicknames.

The giant kitty lives with William John Powers, a doctor in Farmington Hills, Michigan, who also calls Fenrir the Big Chungus, or the Chonk, he said in a Guinness video about the cat. “He just grew and grew, like Clifford the Big Red Dog.”

Fenrir is an F2 Savannah cat. Savannah cats are a hybrid between a domestic cat and a serval, a wild cat native to Africa, and F2 refers to the fact that he’s from the second generation of his distinctly different parent types. And although Savannah cats tend to be tall, averaging 14-17 inches (35-43 centimeters), he’s an inch (2.5 centimeters) taller than that highest average mark. Powers says the height is measured from the cat’s shoulder blades when it’s standing up on all fours.

Fenrir’s height lets him do things other cats can’t. The video shows how he can simply stand on his hind legs and paw at a door handle until the door opens. And since he’s a big eater, he “tends to steal things off the countertop,” Powers says.

He’s also still growing. Though he holds the world record for tallest living cat, his brother, Arcturus (who, sadly, died in a house fire in 2017) holds the all-time tallest cat record. Arcturus was 19.05 inches (48.4 centimeters) tall. Though the cats didn’t live at the same time, they have the same parents.

Powers also lives with Altair, the cat with the world’s record for longest tail on a living domestic cat, at 16.07 inches (40.82 cm). And another cat Powers lost in the 2017 fire, Cygnus, still holds the all-time longest tail record, at 17.58 inches (44.65 cm). Both Altair and Cygnus are Maine Coon cats.

Powers speaks movingly in the video about trying to save his cats from the fire, and being uncertain about adding new cats to the family, knowing his beloved pets could never be replaced.

“It was really hard because at first I almost kind of resented the cats that I got, because they weren’t the same cats, they were different,” Powers said. But the first cat he acquired after the fire, Hyperion, “sort of helped heal my soul,” he said.

You can follow Fenrir and the other Powers cats on their own Instagram account.