From the main menu, go to versus mode, and then hit V to set up the CPU opponents. All of them must be set to level 10.


Hover over "Team Arena" as your game mode, but don't select it. Instead, use the down arrow to set match length to 3 (allowing for quicker restarts if/when you fail), and down once again to change the rules. Here, select "custom rules," and make sure that you turn on shields (select "Merlin's Bubble"), and give every player a mixture of "Ice is Nice" (snowflakes) and "Over Easy" (eggs).


If you haven't played enough to unlock those, go do that! The game is fun when you're not going for this achievement, I promise!
You can also easily unlock the "My Precious" achievement here by selecting a loadout that fills your character's inventory completely. (It will pop once the match begins)

Now, select "Team Arena," and then press V to set up the teams, making sure that you are on one team, and all three CPU opponents are teamed up against you.


Select "Jaws of Justice" as your map on the next screen.


Now for the hard part.

Other strategies exist (and I encourage you to experiment! This likely is not the most reliable strategy!), but the goal of this one is to crush your opponents with this map's environmental hazard: the jaws of justice.


Computer opponents are bad at moving when frozen (even at level 10, thankfully), but it's entirely possible. Rapidly press the catch button ("C" on keyboard by default) to push yourself in the direction you are holding. When they are chickens, they are entirely incapable of moving (the same goes for you though, so watch out!), making them easy to crush.

So, freeze them when they are in the center of the playfield! If they freeze you, simply escape by pressing catch rapidly and holding the stick in the direction of your escape route, and once you've escaped, TF everyone into chickens!

Interestingly, the Over Easy powerup effects everyone, including teammates and yourself (which is why you need to escape before using it), so it is likely that CPU opponents will doom themselves by turning themselves into chickens.

Now, just avoid the ball, keeping it out of your opponents' possession. They are much deadlier with the ball than they are with power ups, which opens up plenty of other possibilities for getting this achievement on other maps!