Fin

Fin is the first slime worth getting attached to. At 1 in 8 almost everyone rolls one early, and unlike Sunset it actually carries fights, which is why it sits at Tier B as the best early carry of the common tier.

Keep Fin equipped until your zone enemies start out-scaling its damage, then hand the slot to a mid-game farmer like Orca. The transition usually happens around the third or fourth zone, when Fin's hits stop one-shotting the mobs you used to clear casually. There is no shame in benching it then, because Fin's job was to get you through the early grind, not to stay on your team forever.

It is the cleanest proof that progression in this game comes from showing up and clearing zones, not from waiting on a lucky pull. Players who equip Fin and keep rolling consistently land Leafy and Meow alongside it, then graduate past all of them by the time Spike or Orca shows up. Treat Fin as the slime that teaches you the rhythm: equip, clear, replace, and never agonize over a common that has already done its job.