Hashirama's "living clone" is a non-sentient clone of Hashirama Senju created by Madara Uchiha in order to harvest his unique abilities.
Appearance
It takes the form of a Hashirama, with eight hands suspended inside some stem like object with spike-like appendages, connected to the giant lotus that rests underneath the Demonic Statue of the Outer Path.[1]
Role
When Hashirama fought Madara Uchiha at the Valley of the End, Madara was believed to have been killed. Recalling this event, Tobi does not deny this defeat but insists that the purpose of the battle was to collect some of Hashirama's DNA which he used to create the clone and further his plans.[1] This "tree" also helped to sustain Madara's nourishment during his twilight years.[1]
After Kabuto Yakushi captured Yamato and studied Hashirama's DNA in Yamato's body to strengthen the White Zetsu Army, he suspends Yamato in the stem, facing the clone.