The Tree of Wisdom was a tree grown by Rotor Walrus. The tree's fruit was able to boost mental intelligence to anyone that consumes the fruit, but in all the years Rotor had it, he was only ever able to grow one. Tails ate that fruit which gave him great intelligence. He became so intelligent, that he thought with his brain-power, he could take on Dr. Ivo Robotnik by himself and have him surrender. Unfortunately, the fruit's affects were temporary and stopped just as soon as Tails entered Robotnik's headquarters and he had to be saved by Sonic the Hedgehog. (StH: #14)