Kangaroon is a boss from "Mole Mania", an action/puzzle game made by Nintendo for the Game Boy in 1996. If you've never heard of the game... don't be surprised. It's something Shigeru Miyamoto thought up and created, but after the game had its initial run, people mostly forgot about it and he never revisited it. Not that it's bad or anything... it's actually a really good game. It's just one of those things that fell under the radar, which is unfortunate. Thankfully, the game was re-released on the 3DS Eshop in 2012, though whether it helped spread it's good name or not, I cannot say.
Anyhoo, Kangaroon is the boss in stage one... which is unfortunate for him. Level 1 is meant to ease new players into the game, so they can get used to the mechanics and how the overall game works. Because of this, the stage is pretty easy... and that reflects true on the boss himself. He'll either throw apples at you or jump around... and jumping is when he's vulnerable. When Kangaroo leaps high into the air, the player character moves one of the two spike objects under him, which will make him take damage. Do this three times, and you win. Kangaroon does return near the end of the game before the final boss, where he's slightly tougher... but not by much.
Strangely enough, despite wearing boxing gloves... he never uses them! He'll either throw apples or jump around... that's it. Why even have them, I haven't a clue.
(Regarding the picture... I can't quite put my finger on it, but I swear I'm missing something I usually do, or I screwed up on something perhaps. I don't know... maybe it's just my imagination? Then again, maybe it's his right boxing glove that's throwing me off. I'll try improving it later.)
I touched up the white outline around him a bit, changed the angle of his nose, and added the sleeve of his right glove. I also altered the background a bit by including the spike traps (mentioned above as how you damage him during battle).