There aren't very many fish goddesses from ancient Egypt. (Okay, we're exaggerating—there's actually only one.) So if you see a fish goddess, and she says she's from Egypt, you already should know who she is. If you still aren't sure, here are some other ways to tell if you're dealing with Hatmehit.
Build: In human form, I'm built like a woman with a fish on her head, or a fish's head on for a hat, or a woman with a fish's head. In fish form, I'm build like a Nile perch (tilapia), wearing the horns and sun disk headdress that Hathor and/or Isis sometimes wear.
Complexion: As a human lady, I'm light-skinned yellow like all Egyptian women in paintings. As a lady fish, however, I have blue or silver or white scales.
Hair Color: As a human I wear a dark wig; as a fish, well, it's all about the scales, baby.
Facial Hair: None, no matter my form.
Scars/Marks/Tattoos: Mar this beautiful body? I think not.
Jewelry and Accessories: When I'm doing the whole human schtick, sometimes I wear golden bracelets and, on occasion, a golden collar around my neck.
Clothing: In human form, I love to don a tight-fitting sheath-style dress.
Type of Weapon: None
Horus the Younger
Huge malls with nice fountains in the middle