Im not sure where to get it but this variety is called Zamia furfuracea "Monstrose". Try searching that

Those certainly look different. I've got some large Z. furfuracea. Those look like they might be a cross/hybrid. Or perhaps a chemically induced mutation.

@statenislandpalm7a and tropicbreezent:

Any idea where I can buy Zamia furfuracea "Monstrose" or other mutated Zamia?

Particularly looking for Zamia with short stems, chubby and somewhat irregular shaped leaves.

I have no idea. Where did you get those photos from? That could be a clue where to start looking.