Brainy Yak is a minor villain from Robotboy. He is a highly intelligent yak that used to be Professor Moshimo's childhood friend from his farm.
When Brian was born he was a very dumb and unintelligent yak. The other yaks made fun of him. Moshimo felt sorry for him and decided to make him smarter by giving him a synthetic brain. The result was that Brian became smarter then any other Yak. But he became so intelligent that he couldn't stay at the yak farm. He walked away one evening to never come back, angry at Moshimo for making a freak out of him. Later he spend his time telling people weights on a circus and selling answers to schoolchildren. His goal is to get revenge on Moshimo.
- His name is a pun on the word Maniac.
- His name is also a pun on the populair British science show: Brainiac: Science Abuse presented by Richard Hammond (also known from Top Gear.)