Predator

Why do koi always swim in groups of 4?

So that while the A koi, B koi and C koi escape the predator will always go for the D koi

The swordfish doesn't have any natural predators to fear of ...

... except for the penfish, which is thought to be even mightier.

We should have a TV show where illegal immigrants hunt down sex offenders for a chance at citizenship

We can call it "Alien vs Predator"

What do you call a fight between a Mexican and a priest?

Alien vs predator