7x39 - Adventure Time

After Finn accidentally causes Susan to be shocked, her cybernetic implant activates, She turns into a mindless drone and attempts to capture Finn. In the process, a chance blast of energy from a gumball guardian causes Susan to grow into a hulking monster. Finn and Susan eventually arrive along the shore, where they engage in a fight. During the fray, Finn's grass arm attempts to harm Susan, and Finn resists. It eventually detaches from his arm and merges with the broken Finn Sword, creating a mysterious grass-hybrid creature.