In the Dungeons & Dragons fantasy role-playing game, the Oaken defender is a Plant. They resemble enormous (30 feet across) disks made of dirt, wood, moss and dry leaves, with six vine-like tentacles protruding from the rim at roughly equal intervals. The topside of the disk has what looks like a huge, angry face made of stumps and roots set into it. Oaken defenders appeared in the Monster Manual IV.
Oaken defenders live in dryad groves and assist in the defense of such places. They spend most of their time sleeping dormant, just beneath the soil and leafy canopy of their habitat, but sense when they or their grove is being oppressed, and rise out of the ground to defend them. They attack with brute strength, and with their 6 woody tentacles. Their enormous mouths are not used for combat, only for feding. The two "eyes" set into the face on the top of the disk are not actually eyes, but heat sensitive lumps which can detect movement and allow them to see almost as if they were not blind.
Oaken defenders speak crude Sylvan.
They are regarded as neutral in alignment.