Phobos and Deimos

Phobos and Deimos were Rei's guardian crows, owned by Hikawa Shrine, where she works as a priestess, and were her guardians.

In the manga, Phobos and Deimos were given human forms, and gave Sailor Mars the Mars Crystal. They were named after the two moons of Mars, a pun on Rei Hino's being Sailor Mars.

When they were in human forms, they wore leotards, black-winged front bows and lilac, enlarged, extended back bows. Phobos' colour was purple, and Deimos' colour was red.

In the Stars arc of the manga, it is revealed that they are from the planet Coronis, and that they were acquaintances of Sailor Lead Crow. In the anime, they only appeared as crows, never in human forms.

Phobos and Deimos Pretty Soldier Sailor Moon
Phobos and Deimos are mentioned by Sailor Mars in the game as a stunt attack.