A female mountain biker, esp. one who likes it rough, rocky, downhill & other fun terrain (opposed to straight & flat) and is really passionate about it (ride or die), as much as the boys are.
The exponential increase in psychedelic consciousness after ingesting a hallucinogenic drug. Once arriving at the climax of the trip, the initial "riding of the tiger" has ended.
"Hey Mike, do you have those shrooms?" Mike- "In my belly.".... "I'm ready to ride the tiger."