Oak-a

Oak-a are elemental monsters of the forest. Their name is derived from "oak", a species of tree, referring to its ties with the forest.

Biology
Oak-a are small, green-skinned creatures. They can be seen levitating to move around and rarely walk, despite having feet. A large helmet of reddish wood can be seen on their head, with a ruffle of leaves growing at one side. They do not have any eyes. They do, however, have a mouth filled with sharp teeth, despite not needing to feed.

Oak-a are ethereal beings, not needing to feed or reproduce. Their habitat is a secluded grove surrounded by a force field that prevents entry from non-Oak-a. New Oak-a simply appear occasionaly at this grove. They are technically immortal, though they can be still felled in combat.

Behavior and abilities
Oak-a are one of the possible summons for Jujutamus. They have questionable loyalty when summoned, sometimes outright returning to their grove immediately after being summoned. Experienced Jujutamus can more easily convince them to stay with them.

Oak-a are capable of doing the following.

Forest roots. No matter how far the Oak-a, it can instantly warp back to its grove. The Jujutamus cannot call the user Oak-a again for a period of time.

Wood aegis. The Oak-a's body temporarily vanishes, leaving behind a levitating wood helmet. The helmet is then enforced with forest magic, exponentially increasing its durability and blocking most attacks from striking it and/or the Jujutamus that summoned it.

Battering trunk. The Oak-a rushes at a target head-first, stopping on collision, attempting to knock the target back.