Francis Grimes believes that the vampires are responsible for the "Mad Larry Disease" outbreak in the city. He tells Mark Lilly that Katrina handles the blood for the vampires. She works with Johnny Three Fangs and Hepcat Chet.
As it turns out, Katrina takes the blood only to help with Blake's father's medical research on the cure for the disease.
- Her looks and name are taken from Katrina from the 1986 movie Vamp