What's the only mammal that cannot jump?
I am willing to bet that you are looking for the Elephant. There are many sites on the web which have stated that the elephant is the only mammal which can not jump. This is NOT the truth.
Just on the Web alone there are several others listed including the okapi, guinea pig and raccoon who are also reported as not being able to jump. (see references).
In the same class as the elephant, both Hippopotamus and Rhinoceroses come closer to skipping than jumping. Like the elephant, their body mass is too great in relation to their mass.
In addition, all bats have weak legs and usually have trouble walking, let alone jumping.
It has been recorded that sloths move too slow to jump. Plus they seldom climb down out of their trees.
Giraffes are known to run, but apparently always have one “foot on the ground.” Due to their neck structure, it may not be possible for them to jump in the usual meaning of the word.
Due to their odd physical shapes and relatively slow speeds, echidna (spiny anteater),
duck-billed platypus and koala might also be listed among the non-jumpers.
Finally, there are the non-land mammals most of which can come at least part way out of the water, but none have legs and by definition, can not jump. These would include whales, porpoises, dolphins, manatees and maybe even sea lions.
Also this:
Urban Dictionary: Hippo Jump