So this is something I've been mulling over a little, and I think, with some tweaking, it could really work. You'll probably need mods for it to work properly, but it could be worth it.

So, you have a base with a big circular room in the middle. Four entrances. Above and below, two prison cells. To the left, and right, whatever you want, but something reinforced would be best.

Take two prisoners- or more- and place them in the cells. Make the top one blue, the bottom one red. Inside the room, place a Thrumbo- or whichever genetic hybrid you'd prefer. Thrumbolope, maybe.

Arm your prisoners with weapons. The shittier the better, but allow them weapons. It's only fair.

Make sure your colonists are a long way away, or, if nearby, very very securely stowed away.

Activate one of the psychic animal emitters that make animals go murderous.

Let the good times roll. Your prisoners will try and defened themselves. If they die, then good- more skins for hats.

IF they live? Replace any lost limbs with prosthetics.

If a prisoner lives successive times, upgrade their limbs.

In the end, you'll either have no prisoners but plenty of hats, or one prisoner that really shouldn't go round magnets at all.

Thoughts?