Hal Stewart is Dex's adoptive Earth father, a full-time handyman and part-time inventor. His personal workspace is filled with assorted junk and recycled parts. Hal often assembles a weird invention in his spare time which sometimes backfires. He has, however, invented very useful items with some help from Dex. One of his more successful creations is the alien detector alarm that goes off when Count Dregon or his agents come within the radius of the house. Hal was at one point allergic to animal fur, though he had seemingly developed a tolerance as he no longer sneezed around Ferbus.