There are many mammals that are unable to jump. Elephants, hippos, manatees, seals and other aquatic mammals, sloths, burrowing subterranean rodents such as moles, etc.

Many, many mammals can jump, the majority of them can.

no they are actually the only mammals that can not jump.

Yes, the elephants are the only animals in the world that cannot jump. All animals can jump; fish, bird, insects, even rhino when they run there's a time in which all the legs are on air, and even the crocodile can do jump, but there is no time in an elephant's move in which the 4 legs are on air. And this is the only animal that cannot do so.

-Rigo Pear. Dominican.

The elephant is reported to be the only animal that cannot jump.