Mindspur of the Depths
The Mindspur is a tentacle segment one inch in diameter, from a creature deep below the surface. Wizards and others of their ilk driven to knowledge have formulated a technique to alter the tentacle length to provide increase mental prowess typical of the species. A properly prepared tentacle with dig into the exposed flesh of a living beings head, worming it's way beneath the skulls. The use of this item is not without cost, as the use gets a hunger for the brains of the sentient and under examination the presence of the tentacle can be seen writhing beneath skin.
Once in place the character gains a +1 to intelligence, but only as long as he consume the brain of another member of his species once a year. Failure to consume the brainmeat results in a loss of the gained point of Intelligence and the doubling of the hunger (i.e., two brains a year). The tentacle can only be removed through the use of magic or the death of the host.