A retaining wall block and method of forming a retaining wall block are provided. The block includes front, back, top, bottom and side surfaces. The top surface of the retaining wall block includes a set of protrusions and the bottom surface includes a channel for engaging with the protrusions of adjacent blocks. Side surfaces of the block are tapered from the front surface to the back surface. A block form and a method of securing a stabilizing sheet to a block are also provided.