Why haven't I drawn Kangersome in a while? Because Marmera's just plain cooler. So why does Kangersome get a Mega form and not Marmera? Because a lot of Mega forms are due to popularity. Not just in appearance, but in the meta game too. Take Kangersome for example. Obviously he's, well... anything said about his appearance is based on opinion so let's move on to abilities.

Kangersome's HP, Attack, and Defense stats are incredibly high, however it's special stats are below average. In addition, it's speed stat is at a whopping 1 base stat, making Kangersome the slowest Pokemon real or fake. But with his bulk, he can work around it. His signature move is called "Not So Fast." This move grabs and stuns the opponent, dealing a little damage and allowing Kangersome to go first next turn. In addition, his hidden ability, "Bypass," allows him to ignore priority moves. Not So Fast paired with Bypass give him the indefinite first go next turn.

In Mega form, his stats get boosted, including his S. Attack which gets a nice sized boost. But his speed stays the same. However, in Mega form, his hidden ability now becomes his only ability, so he can continue doing what he does best: 2KOing everything in his path. Kangersome is a Pokemon designed to show the imaginary meta game that speed isn't everything.