She may play a blood sucker on film, but in real life, Rachelle Lefevre is encouraging her fans to donate blood to Red Cross. The “New Moon” villainess is asking her Twitter followers to donate blood to the organization.

The 30-year-old actress posted a challenge to her fans, writing on the microblogging site: “The challenge – My part: For every 500 new followers I’ll donate 0 to Red Cross, up to 00.”

“Your part: Give blood. Donating blood is fast, free, & saves lives. Give 2 Red Cross or your local org! [sic]“

Lefevre, who played Victoria in the first two “Twilight” films, currently has over 179,800 followers. She also regularly hosts other charity challenges on the website.