Station

Described as the "most brilliant scientist in the entire universe", Station is a peculiar life form which can exist in two different states: in his normal state, "Station" is actually two small beings, which appear to act in a constantly playful fashion. But whenever he has work to do, the two "Stations" merge together into a larger, humanoid form.

In his usual form, "Station" communicates in some kind of high-pitched alien language, whereas his larger humanoid form seems to be only capable of repeating the word "station", in a deep guttural voice.

Bill and Ted refer to Station as a Martian, but there's no confirmation that he actually hails from the red planet; only that he isn't from Earth.

History
In the future, the villainous Chuck De Nomolos attempts to alter history by sending evil robotic copies of Bill S. Preston and Ted Logan back in time in order to kill the original Bill and Ted and steal their identities.

The mission is accomplished, but Bill and Ted's spirits manage to trick Death and convince him to help them in their attempt to defeat their evil robot selves and save their girlfriends and their band. While visiting the afterlife, they ask God for advice and are told to get help from Station, who gladly concedes to assist them.

Back on Earth, Bill, Ted, Death and Station visit a hardware store in order to gather the material they need to build good robots that could defeat the evil robots.