Smollusk

Flying, hexproof
Smollusk Undefeated — The owner may pay a
specified amount of mana on their turn. The mana
payed goes into a mana pool exclusive for this
creature. The mana in that pool cannot be used,
and does not disappear. If that mana pool reaches 20
mana, discard this creature, and all mana in that
pool, then search your deck for an AI Jelleton. You
may place that creature on the battlefield
immediately, without paying any mana.