Lupa is the immortal Roman wolf goddess who, in the Percy Jackson series, trains demigods in the ways of Rome at her Wolf House, then sends them to Camp Jupiter where they can join the twelfth legion.
Lupa is known to be harsh and judgemental towards people, mortals, and gods. She only respects the strong, as any demigod who she judges to be weak is devoured by her and her wolves. She also doesn't seem to care about the hierarchy among gods. Yet, despite her militaristic personality, Lupa has a soft side. For example, while strict, she is not above making the occasional joke.
She is described in wolf form with beautiful chocolate red fur and eyes as silver as mist. She is also described as being very tall, taller than any human. In Jason's dream, she was seven feet tall.
It is implied that Lupa is quite powerful. For example, being the wolf goddess, she has control and divine authority over all the wolves in the world, except the lycanthropes, who are the followers of Lycaon. It is implied that she is very strong and skilled in combat. She also has limited Hypnokinesis power.
Her name, Lupa, comes from the Latin word for wolf, lupus, translating it to she-wolf.
(Thanks to gforce151 for requesting this creature!)