Invented in 1818, the "Dandy Horse" was an early version of which form of transport?

The dandy horse, a derogatory term for what was first called a Laufmaschine (in German), then a vélocipède or draisienne (in French and then English), and then a pedestrian curricle or hobby-horse, or swiftwalker, is a human-powered vehicle that, being the first means of transport to make use of the two-wheeler principle, is regarded as the forerunner of the bicycle. The dandy horse is a foot-propelled vehicle, powered by the rider's feet on the ground instead of the pedals of later bicycles. It was invented by Karl Drais (who called it a Laufmaschine "running machine" in 1817, and then patented by him in France in February 1818 using the term vélocipède. It is also known as a Draisine