Rad Rat is an Uncommon Sidekick that joins Fortnite through the Item Shop, adding a small radioactive rodent companion that trots alongside your character and reacts to the action around it. It arrived in Chapter 7, Season 4 and belongs to the Totally Rat-ical set, carrying the tagline “Just a little radioactive.”
Quick answer: Rad Rat costs 1,200 V-Bucks in the Sidekicks section of the Item Shop, and you lock in its colors permanently right after purchase.
What Rad Rat is and what it costs
Rad Rat is a pet-style cosmetic, sold under the Sidekicks category with an internal ID of Companion_NibbleMoss. Its store page lists the price at 1,200 V-Bucks and marks it as part of the Totally Rat-ical set. You can complete the purchase from inside the game or through the official Rad Rat Item Shop page.
Sidekicks follow a shared set of rules. They react to events and actions in the world, but they cannot spot enemies or items for you. In Battle Royale, only your teammates can see your Sidekick, and visibility can differ in other Fortnite experiences.
The pet is usable across several modes, including Battle Royale, Reload, Fortnite Festival, LEGO Fortnite Odyssey, and LEGO Fortnite Brick Life.
The permanent one-time customization
Right after you buy Rad Rat, the game runs a one-time appearance setup. These color choices are permanent. Once you lock them in, the only way to get a different combination is to buy the Sidekick again, so it is worth deciding on the look before confirming.
The setup covers three color channels, plus a warning screen and a name field.
| Channel | Options |
|---|---|
| Base fur | Black, White, Brown, Grey |
| Accent (hands, feet, tail) | Green, Pink, Purple, Blue, Orange |
| Eyes + FX (eyes and glowing aura) | Green, Purple, Yellow, Light Blue, White |
After the colors, a review screen shows the finished pet and asks you to confirm the lock-in. The final step names the Sidekick. Unlike the colors, the name can be changed anytime later in the Locker.
Locker styles you can change anytime
Separate from the locked colors, Rad Rat carries a set of styles you can switch freely in the Locker. Some are unlocked from the start, while the vests are earned through quests.
- Outline: toggle On or Off.
- Vests (quest-locked): Off, Rad Rat, Pizza, or Camo.
- Reactions: an icon you can choose, like a Fractalized Heart or skull.
- Built-in emote: Rad Rat’s Tag.
The built-in emote, Rad Rat’s Tag, shows the rat rattling a spray can, sending a burst of glowing green smoke upward, then marking the ground with a green rat tag.
How Rad Rat behaves in a match
Once deployed into Battle Royale, Rad Rat runs its own set of animations tied to what you do. It responds to petting through an on-screen prompt, reacting happily and playfully stumbling backward when you interact with it.
During movement, the rat scampers to keep pace as you sprint, slide, and jog around the map, running and bounding alongside your character.
Its remaining reactions cover idle moments and key events during a match.
- Idle: It noses around the ground, uses its paws to clean its ears, then settles into a seated position.
- Weapon fire: turns hostile, snarls, and makes angry squeaking sounds when guns go off nearby.
- Emotes: performs a synchronized dance alongside your character.
- Chest opening: bounds over and rubs its paws together in the manner of a cartoon villain.
Taken together, Rad Rat is a straightforward companion cosmetic: a fixed color scheme you set once, a handful of swappable vests and toggles, and a personality that comes through mainly in its match reactions. If you like the radioactive rat look and don’t mind that the paint job is final, the 1,200 V-Bucks buys a pet that stays visible to you and your squad across most of Fortnite’s modes.
