Pen Slot Optimizer: Which Pets to Equip - Steal An Egg

Which pets deserve a slot?

List everything you own — including duplicates and benched pets — with base $/s and mutation. Set how many Pen slots you have. The ranking shows who makes the cut and who is dead weight.

What is the formula?

effective $/s = base $/s × (1 + (mutation − 1))

Pets are sorted by effective $/s; the first N (your slot count) are “equipped”. The weakest equipped number is the bar any new pet must clear. Benched income is what your spare pets would add if you had the slots — if it is large, a Pen upgrade beats another egg run.

Multipliers are the current set from the mutations guide. They stack additively when a pet has more than one.

What would one more slot add?

The one more slot would add card shows the income of your best benched pet. That is exactly what the next base level earns you. Put that number and the level’s price into the upgrade payback calculator to see how quickly the upgrade pays for itself.

Will a new pet make the cut?

Use Test a new pet before a risky run. Enter the base $/s of the pet an egg would hatch and its likely mutation. The tool tells you whether it goes into a free slot, which pet it would replace and for how much, or whether it would sit on the bench.

How do I use the cut line?

Before a run, look at the weakest equipped value. If the biome’s best egg hatches below that number even with a Golden roll, the run only pays off as a fuse ingredient or index entry. Base incomes by biome are on the all pets list; rarity-to-income bands are on the rarities page.

What should I do with benched pets?

Three plain copies of the same pet go into the Fuse Machine — run the fuse or keep calculator to see whether the result clears your cut line. Single benched pets you will never equip can be sold; keep one of any limited-time pet for the index.