Butterfly

The butterfly is a double-inversion element consisting of two half-loops connected at a relatively low apex. Like the sea serpent (two half-loops connected at a high peak), it produces two full inversions without changing the train's direction. The butterfly's lower connecting section distinguishes it from both the sea serpent (higher apex) and the bowtie (different geometric proportions) and from the batwing (which has an embedded direction change).

The butterfly is not a widely built element and appears on a small number of Vekoma and custom coaster designs. Its double-inversion nature in a compact vertical footprint makes it attractive for layouts with space constraints. For enthusiasts it represents one of the more obscure entries in the inversion taxonomy — a useful illustration of how many variations designers have found on the basic geometry of turning riders upside down.