UltimatestarA compound of Ultimate Skewb (hence the name) and Icosahedron Skewb.
VegamateA pentultimate in shape of a compound of five tetrahedra.
VegaminxA megaminx in shape of a compound of five tetrahedra.
X 3x3x3A 3x3x3 without twelve pieces but extended to a X-like shape.
X-CubeA 3x3x3 with a concave but regular shape.
X-Cube (Brandt)A 3x3x3 truncated mainly on the edges and stickered like two fused tetrahedra.