Steve is a member of SALF, an organization made for the pursuit of aliens and one of the three main antagonists of Scooby-Doo and the Alien Invaders. He disguised himself as an alien to raid the gold underground.
He works for SALF with his two colleagues Max and Laura. Steve is first seen in the station when Max heard something strange from the monitors. Of course he and his friends are convinced that they're in contact with aliens. When the gang came across the station, Steve and his colleagues welcome them. As they talked Velma saw some mud on his shoes (including on the shoes of his colleagues), which makes her suspicious about them. As they spoke they tell the gang that they might be in contact with aliens since they heard something on the monitors.
Of course Steve and his friends then disguised themselves as aliens. They scared Scooby and Shaggy by abducting them, just before meeting Crystal and Amber, but when the gang enter the mine, Steve, Laura, and Max have their cover blown by Velma has their accomplices go to search for Shaggy and Scooby. Then they finally revealed that they discovered the mine was full of gold and they wanted to use it for their own interest.
With the rest of the gang still their prisoners, their henchmen come back and tell them that they found real aliens, which they think was a hallucination because he, Laura, and Max are the aliens, but they realize that they were telling the truth. Realizing the aliens are far more valuable than the gold mine, Steve try to capture Crystal and Amber with his bulldozer, while Laura tries to pry Max who was trapped with their henchmen from Amber, but thanks to Shaggy and Scooby their plan failed when they both crash their bulldozer to his, where it topple and rolled over, much to his discomfort. Steve and Laura tried to escape the cave, but the gang manages to trap them with net. The three SALF members and their henchmen are arrested by the police, Steve saying the ever popular cartoon phrase, "We would've gotten away with it if it Hadn't have been for those Meddling Kids!", only for the police officer to furiously silcenced him as they're put into the van and sent to prison.
- Though he, Max and Laura are collectively the main antagonists of the film, Steve seems to be the leader of the trio, as he was ordering Max and Laura around, as well as the fake MPs.