Play a Super Strength character on Slaughter Swamp's default starting area. Weaken your opponent A LOT. Their health should only have a few notches left. Be near the hanging crocodile's tail with your opponent on the left. Press
to active the Level Interaction and you will grab the croc and slap them with it. If they were weak enough, you'll win the match and pop the achievement. If they had too much health, you'll have to start over on a rematch as the croc is a single-use Interaction.