Her name could come from the fact she's dressed up as a giraffe, however doesn't have the neck of one. Raffi is also a corruption of the word giraffe.
No-Neck Raffi, like her zombie counterpart, doesn't seem to have any special abilities. You can easily defeat her with little to no problem, just stay cautious about the Potato Mines she and her Cactus allies drop. She may also attempt to use Petal Propeller to dodge or get to higher ground.