Bjorn Bjornson and Brother Bjornbot are the recurring villains in the animated show Robotboy.
Bjorn Bjornson is an Icelandic child who attended Professor Moshimo's classes at the "School For the Wealthy and Smart", and is a jealous rival of Moshimo's works and Kamikazi's plans including Robotboy. He has also designed a robot equal in power to that of Robotboy called "Bjornbot". It can be seen in the episode Runaway Robot that he dislikes herrings.and Bjorn and Moshimo called Bjornbot Brother Bjorn. and in the episode Party Out of Bounds fighting his second rival Dr. Kamikazi. He speaks in an accent very similar to Stewie Griffin from Family Guy.
Bjornbot is a robotic lookalike of his creator Bjorn Bjornson. He has weapon capabilities and strength equal to that of Robotboy, and can Superactivate too. At the same time, there can be several Bjornbots fighting at once. It seems that Bjorn himself has created multiple numbers of such bots. Bjornbot even has his own form of Superactivation. Unlike Robotboy, he lacks emotion and has a rather flat vocabulary (which consist mostly of the word "yah!"). Bjornbot also lacks intelligence given Robotboy a chance to use it against him. In the episode Party Out of Bounds he dressed like a girl and Bjorn called his Sister Bjorn. Such as the guest villain Dog-ra and the Recurring villain Protoboy.