If you're going for the max or DLC you'll have loads if chances to get this - just compete wave 5 at the ore chasm or the wildlife preserve etc

Many of the arenas have an opportunity to redo the final wave (or equivalent eg murderlins arena in the tiny Tina dlc). In this case you can import a character who popped this achievement, do the final wave again and...

*pop*

I actually got this on the 360 and then in the xbox one version completed wave 2 of an arena in someone else's game and it popped.