Waddle Dee Toss is King Dedede's Side Special Move. He throws a Waddle Dee forward. Occasionally, he may also release a Waddle Doo or a much more damaging Gordo. Whatever he throws will remain on the battlefield for an unknown amount of time after using the attack. It appears that there is about a 1/10 chance of Dedede throwing a Waddle Doo. Only two Waddle Dees can be on the field at once.
Origin
This is a unique move made for Super Smash Bros. Brawl, though it's not a very big stretch. Waddle Dees, Waddle Doos, and Gordos are all King Dedede's servants, and King Dedede throwing them around is not out of character at all.