This challenge is part of the Trick Shot mission in Chapter 2, Season 1 of Fortnite. It asks you to gain Health with a Small Fry, a Flopper, and a Slurp Fish:
To complete this challenge, we recommend playing in Team Rumble mode. This way, you will find a large number or weapons, will be able to traverse the map easily, and will respawn infinitely until the end of the game. If you join a team, you can share missions with your teammates for quicker completion.
Here is the location of the fish:
The Slurp Fish is a rare fish that gives 50 Health by default, unless your life is already full — in that case it will give you 50 Shield. It is a quite rare fish, so you'll need to be patient to catch it.
Also keep in mind that for Small Fry and 'standard' Fish, you need to have a depleted Health bar in order to be able to regain Health by consuming the food. If you want to progress in this challenge quickly, you will sometimes have to suffer a fall or explosion damage to facilitate this.
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