When she was a child Guinan had an imaginary Tarcassian razor beast as a pet. In her mind it had dark brown fur, gold eyes, and enormous wings that let it fly so fast no one but her could see it. The beast protected her and made her feel safe. When she needed support or comfort she imagined herself lying on the beast's stomach and listening to its purr.
Eventually the image of the beast faded from her mind, but the idea remained. Long after she had become an adult and stopped believing in imaginary friends Guinan still found its memory a great source of comfort, even talking to it in times of fear or confusion. (TNG: "Imaginary Friend")
Guinan once remarked that in her opinion Ro Laren was jumping on her bed, when she was a little girl and that she could barely resist the urge to leap up and start jumping around like a Tarcassian razorbeast when both of them were turned into children again. (TNG: "Rascals")