What is the only mammal that cannot jump?

The Elephant is the only mammal that cannot jump!

Three other mammals that cannot jump are hippos, sloths, and rhinos.

http://listverse.com/2009/02/04/top-10-fascinating-facts-that-are-wrong/

Given its weight and skeletal shape, I would doubt that the walrus can jump either. https://en.wikipedia.org/wiki/Walrus This would probably apply to others like the elephant seal too. Taking 'jumping' in the sense of propelling a body off the ground, that would rule out all the cetaceans too. The dolphins and porpoises do manage to leave the water by high speed swimming, and this might be counted as 'jumping'. I would doubt the capability of a blue whale to do this though.