Sexy, particularly as relates to sex with anthropomorphised animals, cartoon animals, or sentient animals, any of which may be known as a furry. From yiff.
That vixen is yiffy.
(in furry fandom)
adj. 1. Horny, aroused; 2. Sexy or attractive sexually
1. "Oh God I'm yiffy."
2. "Did you see her? She was yiffy."