Megan looks over the options, "You know that can't possibly work". Driven by her curiosity she selects Will as a subject as well as some random options she can find. Quicker than Will could object she pressed Apply and said to him "See, nothing happens at all".
At first nothing seemed to happen, but suddenly Will felt an intense tingling below his waist. "Ohh shit, it does work" he tried standing behing Megan's computer chair. His lower body started to loose definition, turning into a glittering diffuse blob cloud. Megan watched speechless as that blob got bigger both in height and in depth forming a rather large large cloud behind him. Having no legs Will turned his head and upper body to turn around to see it. The cloud bulged upwards near the rear end and lost contact with the ground near its middle. Gradually it started take shape.
The upwards part of it formed into a simple faux leather seat with an armrest on each side. It was mounted via shock absorbers to what looked like a large near spherical chunk which grew 2 powerful legs on its sides. At first they looked roughly like the hind legs of a horse, but as they formed they turned into mechanical versions of horse legs. Segmented parts covered by beige metal sheets shaped to resemble a horse connected by ball joints. On their ends they ended in what looked like metallic hooves.
The large chunk in the middle also was covered by those metallic plates. It had to 2 circular vents near it's bottom as well as a suspiciously looking grey bulge.
The changes gradually moved forwards and formed a second chunk, connected to the hind one via a flexible joint. It also grew a set of legs, but those were much thinner than the hind ones, yet still capable of supporting the weight put onto them by Will. As the last change, a "TAXI"-sign appeared on the front between the legs, and a grey metallic ring joined Will's waist to the mechanical horse.