The cutaneous rabbit illusion is a tactile illusion evoked by tapping two or more separate regions of the skin in rapid succession. Wikipedia

A perceptual illusion evoked by a rapid sequence of sensory stimuli Wikipedia Disambiguation

A tactile illusion where tapping separate regions of a person's skin in rapid succession (e.g. the elbow and the forearm) gives the impression of sequential taps "hopping" from one point to the next, even though the intermediate points were never touched. Wiktionary