Gigachess was the first chess variant to use both the Elephant and the (War) Machine, called Ninja Guard and Ninja Warrior here. The Gryphon-Hippogriff page provides some historical background to pieces like the Stealth Gryphon. My Spotted Gryphon thread includes my Spotted Hippogriff, which was based on a piece invented by Peter Aronson.
Gigachess was the first chess variant to use both the Elephant and the (War) Machine, called Ninja Guard and Ninja Warrior here. The Gryphon-Hippogriff page provides some historical background to pieces like the Stealth Gryphon. My Spotted Gryphon thread includes my Spotted Hippogriff, which was based on a piece invented by Peter Aronson.