After getting turned into a werewolf by her sister Kate, Tasha embraced her nature rather than controlling her instincts as Kate did. As part of this, Tasha decided to create her own pack and turned Brandon and Travis into werewolves for this purpose.
After tricking Kate into leading them to Tasha, the Winchesters were confronted with her pack. Though Brandon and Travis initially had the upper hand through the element of surprise, they were quickly and easily dispatched by the Winchesters. Realizing that the sister she loved was gone, Kate killed Tasha herself, ending the pack.