The Makai Tree (魔戒樹, Makaiju) is a tree-like creature that resides in the Makai Forest. She kept Jabi within her stomach. Inside her stomach, the Makai Tree's a round squid-like creature with multiple eyes. She has many tentacles and can shoot spears out of her "body" to defend herself. She's not a malicious creature; she kept Jabi sleeping inside her stomach for a 200 year incubation. She claimed that Jabi wasn't ready to reincarnate (hinting the Makai Tree had plans for Jabi) when Kouga came to save her.
Kouga at first had to fight off the Makai Tree's illusionary attacks. The Makai Tree has the ability to take on the forms of people within the memories of Kouga. For Kouga it as easy when Barago, Kodama, and Rei appeared, but the most difficult was when Kaoru and Taiga's form was taken. Eventually Kouga learned to suppress his feelings just long enough to defeat the Makai Tree on the first round. During the second round Kouga had Gouten increase the Fanged Wolf Horse-Slashing Sword twice its size and surfed the sword into the Makai Tree's stomach. The Makai Tree's stomach exploded and Jabi was saved. Jabi was spirited back to the living. The Makai Tree was only defeated, not destroyed.
The Makai Tree is voiced by Yukari Okuda (奥田 ゆかり, Okuda Yukari).