The sixth generation of Pokémon games is here, folks. Pokémon X and Pokémon Y are available now, with a massive number of new pocket monsters to collect and force to fight to the death. It's a good time to be a gamer.

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In honor of the new games we wanted to revisit some of our favorite evolutions in the series. They include Pokémon that evolved into something they shouldn't have, that evolve in a strange way, or that evolved unexpectedly—or that we just really like. There are tons to choose from, but it wasn't too hard to narrow it down to these 20.

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There are also plenty of crazy new evolutions in the new games—including a brand new type of evolution called the Mega Evolution. We've barely scratched the surface of what's in X and Y, though, so that list will have to wait for another day. Read on for our 20 favorite Pokémon evolutions.

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