The Signature Series was a program where an artist would design a model, and then the Stone Co employees painted them. Each model had a stylized sticker of the artists' signature, and came with a Certificate of Ownership.
Boggle is a bay leopard appaloosa TWH designed by Sarah Minkiewicz-Breunig. There is a Non-Custom version and a Custom version. The Custom version has a longer lowered tail. This run was available in matte finish. The total run of both custom and non-customs was 250. However, I've heard only 5 of the custom version were made.