Presently, there is no Champion that has a Hive Mind mentality, one that is part of a massive swarm of creatures. The Zerg (Starcraft), D'Vorah (Mortal Kombat), The Flood (Halo), the Borg (Star Trek), and various others are good examples of Hive Minds.
It would make for a particularly interesting (and nightmarish) Champion to use the Hive Mind/Swarm motif. But would this be inappropriate for League's lore? Would it simply not fit? Or could the story team find a way?