A heffalump is a creature mentioned in the Winnie the Pooh stories. Original books depict heffalumps as looking very much
like elephants. Pooh and Piglet fear heffalumps, and in an attempt to cover their fears they attempt to bravely capture a heffalump in a
trap. But no heffalumps are ever caught in their
trap, and indeed no heffalump is ever met within the course of the books aside from those that appear in Pooh’s nightmares, wherein they are very fierce and are intent on stealing Pooh’s
honey.
A heffalump has also become a term of abuse for a fat person and or
oaf, similar to Jabba, as in Jabba The Hutt.