I have some mechanical spider "masters" I've been working on for a while. They got shelved for a while due to other projects (wonder what that could be?). But I'll try and get them done once the current madness has passed.
They aren't designed to be steeds, but I could probably make a simple change to allow that... anyway, must finish the current things, although my daughters lack of sleep, or rather my lack of sleep due to her, is making that difficult.