Jacko Spaventosa

Jacko Spaventosa is a mythic-tier brainrot in Steal a Brainrot, the Roblox collection-and-trading game where every pet generates passive income and can be upgraded with mutations and traits. At base, Jacko Spaventosa earns $16.3K/s and costs $4.9M from the in-game shop — those numbers are the floor, before any multiplier from mutations or trait stacking is applied.

It is obtained via Fusing it in the Witch Fuse with Mythics in-game. Verify availability before any trade — Steal a Brainrot regularly cycles which items are obtainable, and a brainrot's market value can swing sharply when the game flips it to limited or unobtainable status.

For trade evaluation, divide the USD value by your offer's value to get a clean ratio. The trade calculator does this automatically and applies trait amplifiers (Brilliant, Sniper, etc.) which add to base income additively rather than multiplicatively. See the methodology page for how the valuation algorithm actually computes these numbers, or the trade-valuation guide for a step-by-step walkthrough.