What is a “cat carrier” in American English?

A cat carrier is a small portable crate Americans use specifically to transport a cat: vet visits, moves between homes, road trips, plane flights. The compound noun is fixed; “cat box” and “pet carrier” exist but mean different things (“cat box” usually means the litter box). American pet stores sell soft-sided fabric carriers for short trips and hard plastic ones for flights. Most American cats hate the carrier, which is its own running joke in pet content. British English speakers often say “cat box” or “pet carrier” instead.

In this clip, a family on moving day realizes a small problem: “I have no idea where the cat carrier is. Looks like they’re gonna be traveling by their backpacks.”