- Poison Attack - One Foe, Normal Attack, Poison 25%
- Scratch - One Foe, Physical
- Bite - One Foe, Physical, Accuracy -30%
- Lick (M) - One Foe(Luka), Pleasure Attribute
- Lick (F) - One Foe, Pleasure Attribute
She's a beast, so she has a lot of high damaging physical attacks, but they're relatively weak alone. But since beasts usually appear in packs, they can be surprisingly dangerous. Additionally, her normal attack has a chance to inflict Poison, which causes the target to lose 10% of their health every turn. It even persists after combat. Cleanse this with Antidote as soon as possible to minimize the damage it does.
You should have recruited Mimi by now, who has access to the Hunter job. The good idea is to use her Beast Killer Arrow, as it does bonus damage to beasts like Rat Girl. The Imps continue to be useful, as she's weak to Pleasure and the associated statuses.
"What kind of hero mates with a rat? Were you that desperate to do it with something that wasn't human? Other than her high agility, rat girls aren't very scary. Her poison can be a nuisance, but it isn't particularly threatening. If they appear in groups, things could get dangerous though. Simply concentrate your attacks and take them down one at a time. The Hunter's Beast Killer skill will do a lot of damage, and don't forget that pleasure attacks are extremely effective too. Now go, oh brave Luka. Throw that rat back into the gutter where she belongs."