Mutations in Be Flash for Brainrots change how a brainrot looks and, more importantly, how much cash it pulls in. Every mutation applies a multiplier to both the brainrot's earning rate and its sale value, and a single brainrot can carry more than one at the same time if you hit the timing right.
All mutations and their multipliers
There are nine mutations in the game right now. Four of them spawn naturally during regular play, while five are tied to timed events that rotate through servers.
| Mutation | Multiplier | How it spawns |
|---|---|---|
| Gold | 1.5x | Natural |
| Diamond | 2x | Natural |
| Rainbow | 3x | Natural |
| Candy | 4x | Candy event |
| Lava | 5x | Lava event |
| Blizzard | 6x | Blizzard event |
| Lightning | 7x | Lightning event |
| Hacker | 8x | Hacker event |
| Horizon | Unknown | Natural (rarest) |
Horizon is the rarest mutation in the pool. Its exact multiplier has not been confirmed, but it sits at the top of the rarity ladder along with the natural spawns.
How the mutation mini-game works
Mutations are tied to a quick-time event that fires while you're charging and dashing through the play zone. One or more mutation icons will flash onto your screen during a run, and you only have a short window to react.
Step 1: Build up Stamina at a treadmill, then head into the Charge Zone and start a dash through the sub-zones. The lucky block you place at the end of the run is what receives the mutation.
Step 2: Watch for the mutation icon (it appears as a thunderbolt-style button). Click or tap it before it fades out. On the controller, use the QTE buttons shown on screen (X, Y, B, A, or the PlayStation equivalents).
Step 3: Let the lucky block roll. The brainrot it produces will spawn with the mutation you successfully tapped. Miss the tap, and the brainrot rolls with no mutation at all.
You can confirm it worked by checking the brainrot's name and appearance once it's placed at your base. The mutation prefix (Gold, Diamond, etc.) will be attached to the brainrot's name, and the visual effect matches the mutation type.
Natural spawns vs event mutations
Gold, Diamond, Rainbow, and Horizon roll randomly during normal gameplay. The other five — Candy, Lava, Blizzard, Lightning, and Hacker — only appear while their matching event is active on the server.
Events run for around 10 minutes once they start and trigger randomly. If you want to force a specific event without waiting, the events podium next to the leaderboards lets you spawn one for a Robux cost.
Stacking multiple mutations on one brainrot
Occasionally, more than one mutation icon will appear on screen during the same dash. Hit every icon before any of them disappear, and the resulting brainrot will spawn with all of those mutations attached.
Stacked mutations combine additively, not multiplicatively. A brainrot rolled with both Gold (1.5x) and Diamond (2x) ends up at 3.5x total — not 3x — because the multipliers are summed rather than multiplied together.
That math matters when you're deciding which icons to prioritize if you can't comfortably hit all of them. A clean Hacker tap (8x) beats a fumbled Gold + Diamond combo (3.5x) every time.
Which mutations are worth chasing
Hacker is the strongest confirmed mutation at 8x, with Lightning (7x) and Blizzard (6x) close behind. All three are event-locked, so the practical ceiling for free play depends on whether you can catch those events live.
For natural spawns, Rainbow at 3x is the best you can reliably grind for without paying to trigger an event. Horizon's multiplier hasn't been pinned down, but its rarity suggests it sits above the event tier.
If you're filling out a base from scratch, the fastest path is to keep an eye on the events board above the Charge Zone, queue up dashes when Hacker or Lightning is running, and use the Lucky x2 Mutation gamepass to boost the QTE spawn rate during those windows.