This Fortnite quest asks you to kill at least three wild predators found across the island.
Only two animals count as predators here: Wolves and Raptors.
You should be able to find both easily enough - here's where you should go.
Fortnite: Where to find predators
The map above shows where you are most likely to encounter wolves and/or raptors. Note that spawns are random, so there's never a guarantee of finding what you want.
Make sure you are armed properly, as these predators can deal heavy damage if you're unprepared -- Raptors in particular are hardy and fast. Make use of structures to protect yourself, too.
Hunting predators rewards you with large amounts of bones and meats, which are useful in upgrading Primal weapons.
As always, be mindful of other players seeking to complete the same challenges in the area.