In the original books and classic Disney movies, heffalumps were only seen as strange creatures that haunted the nightmares of Winnie the Pooh and his friends. They were often depicted as being vaguely elephant-like in appearance, though they were said to be able to morph into any form and also often said to work alongside woozles as honey-thieves. Their supposedly extraordinary qualities were described in the song "Heffalumps and Woozles".
Yet, both heffalumps and woozles were only confirmed to be real creatures in The New Adventures of Winnie the Pooh. A woozle honey thief named Stan and his heffalump sidekick Heff appear in the episode "The Great Honey Pot Robbery."
In the film Pooh's Heffalump Movie, Rabbit decided to form an expedition to take action and stop the heffalumps from stealing honey and ravaging the Hundred Acre Wood once and for all. In the song "The Horribly Hazardous Heffalumps", he and the others outlined some even more dangerous things about heffalumps, such as their fiery eyes and a tail with a spike. With the help of Roo in particular, everyone learned that heffalumps were not so scary after all when they met Lumpy.
A heffalump is actually an elephant-like creature of a pleasantly purplish color with a big trunk, large floppy ears and a small roundish fluffy tail rather like that of a rabbit. Older heffalumps are capable of issuing a call that can travel over great distances and one of the ways a heffalump can tell that it is growing up is if it discovers its special call. Within the Hundred Acre Wood, heffalumps generally reside within Heffalump Hollow, though more recently Lumpy has taken to spending large amounts of time outside of it, playing with his best friend, Roo. True to the original song, heffalumps are, in fact, quite fond of honey. When trying to convince the others that heffalumps weren’t so bad after all, Roo pointed this out as being a similarity that they had with Pooh.