Oddly one of the hardest achievements for me to pull off. In the second room of Clyde's tower, you can get this fairly easily if you're near the end of the game. Hitting the tire with your ranged weapon releases two nazi cats. Use Sneaky Squeeker to lure the two nazi cats and two nazi kids over to the flame, then cup-a-spell. Took me a couple tries, but an easy late game solution for this one.