An alien coil, or alien clapton is a coil design that evolved from the clapton coil. A core of thicker wire (or grouping of wires) is wrapped within an outer coil of thinner gauge wire much like a clapton, but in the case of the alien build, the outer wire wraps are made from wires that have previously been coiled and has been stretched and partially re-straightened before wrapping again to give the waved effect seen in the picture.