A large furred and winged predator which Guinan adopted as her imaginary friend in childhood, and which she describes to Counsellor Troi in the episode Imaginary Friend.
The Tarkassian razor beast is a formidable animal known to the El-Aurians, described by Guinan as covered in golden-brown fur, with huge wings and large spiny teeth.
In the episode Imaginary Friend, Guinan tells Deanna Troi that as a child she chose a razor beast as her imaginary companion. Far from frightening her, it made her feel safe: she would curl up against it at night and it would guard her while she slept. She admits that she still talks to it now and then.
The story is offered as reassurance that young Clara Sutter's invisible friend Isabella is nothing to worry about, a judgement that proves premature once Isabella turns out to be a real and hostile energy being.