Hunt an infected animal
This challenge is quite complicated, as you have to find an animal infected with an alien, and aliens are not as common as normal animals. However, it seems that we find these animals more in the Misty Meadows area, west of the city to be precise. Be aware, however, that we find them everywhere on the map.Infected animals are those that have been contaminated by aliens, which are hanging on their heads. If you kill them, but the aliens stay alive, then they'll latch onto you, doing damage. On the other hand, you will jump higher and run faster. To get rid of it, it suffices, as a reminder, to go into water or fire.