Human Spirit of Wood
The Human Spirit of Earth was created from Ancient Troiamon after his battle with Lucemon in the past. From there it passed to Cherubimon's keeping. When Cherubimon betrayed the Digital World he transformed it into Arbormon. Arbormon is defeated the heros in "Mysterious Warrior Lurking in the Darkness, Duskmon!", but is back-stabbed by Duskmon who seals the Human Spirit of Wood. When Duskmon is scanned in "The Past is Revealed! Duskmon's Secret" Kouji it is assumed that he took the spirit (this is not actually seen) until he gives it to Takuya in "Spirits Become One! Takuya and Kouji's Ultimate Evolution!" to allow him to hyper spirit evolve into Kaiser Greymon.
(Note: Is called Spirit of Wood H in the TCG.)