Humans: Humans aren't aliens, as they live on Earth, where most of the action action takes place. As you know normal humans don't physical powers. Still, there are humans that demonstrate impressive physical powers far beyond those of 'normal' people. They also don't seem to age very quickly. Master Roshi is over 400 years old, and Kulilin doesn't change all that much (at least, physically) in the 20-35 years that pass during the manga run.