Edo-Tensei is the resurrection jutsu. It will summon the "EntityNarutoMob03" entity, that has a Tobirama skin. It doesn't have the edo-tensei eyes shown in the anime, however. When performed, a wood coffin will come out of the ground. Shortly after that, it will disappear and Tobirama will spawn. He has 450 health and will fight alongside the player, doing around 4 damage per melee attack. He also regens 1 health per tick, so it is not easy to kill him.
As far as we know, it is impossible to get Edo-Tensei through normal gameplay, so the only way to get the jutsu item is through cheats, like the TooManyItems mod.