Novice Rebels

Revolt - At the beginning of your postcombat
main phase, if a permanent you control left the battlefield this turn, mature Novice Rebels.(To mature this creature, exile it. If you do, search your library for a non-Young creature card that shares a creature type with it. You may cast it by paying the difference in mana costs between it and this creature. Then shuffle your library.)
At this age they haven't seen much. Who knows
what hero the dwindling ranks may produce.