Dragon

Dragon is a unnamed Dragon-like alien that was captured by the Forever Knights about 1,000 years ago for unknown reasons, and since then they have been testing weapons in an attempt to kill him. In the episode Be-Knighted, he eventually escaped and confronted Ben but his Universal Translator was broken and he fled when Connor tried to shoot him with an alien weapon. Later Ben tracked him down and fought him as Spidermonkey, he eventually replaced the Universal Translator with a new one, and it is revealed that he was trapped and that he is an alien that came to Earth because he was making an intergalactic map. He then tried to kill the Forever Knights, but Ben convinced him not to, he then went back to his planet on his ship. It is unknown if he will return.