Earthlings!!

 

  but it can get a bit confusing as to who in DBZ is from earth and who isn't.  For example, there are 'normal' humans in Akira's world, but there are other, more unusual people or creatures.  Oolong for example, and Mr. Popo are earthlings, as is Tien, they just don't look like it.  Well, I suppose in a world where an alien is God and dinosaurs roan the earth it isn't that unusual.

Just in case you are still confused, here are some characters who are 'earthlings', but might not seem like it;

Oolong,

Puar,

Tienshinhan,

Mr. Popo,

Well, you get what I'm saying, right?  Anyway, just because a DBZ character doesn't look like all the other characters, it doesn't mean they are aliens, unless the storyline, e.g., with Piccolo, says other wise.