Elderwood Blitzcrank
Or really just a nature themed Blitzcrank, Elderwood being a naming convention already used in the game.
I just really like the idea of Blitzcrank as a high-fantasy styled golem, made from hewn stone and held together by vines and other organic matter.
Imagine that instead of a chain, his Rocket Grab is attached via a gnarl of vines and roots.