Raccoon Koopa, similar to Raccoon Mario, is a super-powered form, though this one applying to King Bowser Koopa.
The Raccoon Koopa form only ever appeared in The Adventures of Super Mario Bros. 3 episode "Super Koopa". In the episode, Bowser, through the use of a powerful pendant, gained the ability to conjure and use power-ups, including Super Leaves.
After becoming Raccoon Koopa, Bowser gained a long, raccoon tail, as well as raccoon ears. Using his tail, Bowser could attain flight. As Raccoon Koopa, Bowser possibly became physically more powerful, as he was shown to be able to punch a helicopter out of the sky with his bare-fist.
Eventually, Bowser lost his ability to turn into Raccoon Koopa after his pendant overloaded and exploded, due to using too many transformations in a row.