When Rocco enters, if you cast it, you may search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.
Cast Rocco with as much X as you can afford to tutor any creature with mana value X or less directly onto the battlefield, fetching a combo piece or bomb. From there you grind value, recast Rocco off blink/recursion, and either assemble a creature-based combo or beat down with a swarm. The early game ramps hard so a big X-Rocco lands a haymaker on turn 4-6.
Built-in tutor-to-battlefield that fixes any creature-based plan or combo on cast
Naga GRW colors give the best ramp, blink, and recursion to recast Rocco repeatedly
Flexible: the fetch scales with available mana so it stays relevant all game
Cheap commander (MV 3) that snowballs with mana doublers and cost reducers
The trigger only works if you CAST Rocco, so it's reliant on a 3-mana commander surviving
Tutored creature has no haste and can be killed before it does anything
Vulnerable to graveyard hate, counterspells, and removal on the cast trigger window
Needs ramp to make X large; a small Rocco fetches little of value
Legendary Creature — Elf Druid
