Lupa

Lupa is the immortal she-wolf that raised the twin brothers and sons of Mars (Ares's roman form is called Mars) Romulus & Remus. She is described in wolf form with beautiful chocolate red fur, calculating dark amber eyes, and sharp fox-like features.

History
She is the head of the Roman Camp Half-Blood in San Francisco, California, much as Chiron is head of the Greek Camp Half-Blood in Long Island, New York. She presumably has the same pact with the gods as Chiron does, which means that as long as they are needed to train half-bloods they will remain immortal. Harsher than Chiron, she does not aid or raise weak demigods and runs a harsher, more militaristic camp. She lets the mortal parents leave the baby child in the Wolf House. If they show weakness, she eats the babies. If they show potential, she takes them to the Roman Camp Half-Blood and trains them. She can speak both Latin and English. She is the head of a pack of wolves which rivals those led by Lycaon.

The Heroes of Olympus
Lupa contacted Jason in his dream to warn him about Gaea and inadverdently gives him a clue to his parentage and family.