They look like birds. [Duh...] Two wings, two feet, a beak, and come in an assortment of colors. They have an elegance about them and they're dedicated to their jobs. It's said they can sense the unique signature of a person and that's how they can deliver their messages. Quite impressive, if you ask me.

[Then again, malak can sense other malak, so it's the same. Still, his descriptions such, but he can purple prose a bit...]