Birdy is a telepath and sidekick to Sabretooth. She used what she referred to as the Glow to enter his mind and separate his memories so that he could be more man than animal. Under the influence of the Glow, Sabretooth was able to control his aggression and murderous intent. Together they formed their own supervillian team and hired themselves out as assassins and would also wreak havoc on the X-Men.
In addition to telepathy, Birdy also operated a number of firearms. The most of them seemed to be twice her size. Though they teamed together, their alliance was never an easy one and Birdy was constantly in fear that one day Sabretooth would turn on her.
When it became apparent someone was out to kill Sabretooth, Birdy accompanied him on the hunt. They tracked down Mystique and found out from her that the person trying to kill Sabretooth was actually his own son; Graydon Creed. Birdy confronts Graydon and dies, stabbed to death.