Charlie, a shorthaired black cat, rests in a plush cat cave on top of Sam, an orange tabby cat.

Charlie, a black shorthaired cat, rests on a blanket next to Sam, an orange tabby cat. Sam appears visibly weak and tired.

Charlie, a black shorthaired cat, and Sam, an orange tabby cat, cuddle up around each other (like a yin yang symbol) on a red and white blanket that says "CANADA."

Charlie, a black shorthaired cat, grooms the head of Sam, an older orange tabby cat.

But sometimes Charlie is so goddamn sweet, and I can't fathom how much tougher this summer would be without him. As Sam wastes away from his nasal lymphoma, Charlie has only grown closer with and more comforting of his sick older brother. #BlackCats #VoidCats #BrotherCats #ApartmentCats

Sam, an orange tabby with white chest markings, sits in a cat tree and hisses at Charlie, a black shorthaired cat. Charlie is scaling the cat tree's center pole and grabbing at Sam from the edges of Sam's platform.

Hank, a fluffy tuxedo cat, sits majestically in a cat tree at night, lit by the glow of lamplight. Above and behind Hank, Charlie, a black shorthaired cat, reaches out from the top of the cat tree to swipe at Hank's head and ears.

Charlie, a black shorthaired cat, invades the top shelf of a multi-level window shelf unit for cats, while Hank, a fluffy tuxedo cat, looks out helplessly from behind and underneath Charlie.

Charlie can be a huge asshole sometimes. #BlackCats #VoidCats #CatsAreAssholes #ClimbingCats #ApartmentCats