I believe a common gear used is a cycloidal gear for various reasons.

check: http://www.gearshub.com/cycloid-gears.html

Planocentric replaced the cycloid drive. The Planocentric involute gear also known as a wobble mechanism, used for speed reducing mechanism as an ingenious mechanism.

The length of one arch of a cycloid generated by a circle of radius r is 8r.

No. You can, however, get Cycloid. Exactly. Hammer Gorem, Cycloid, and Tricloid are arguably the three best Sub Terra Bakugan, actually.

terrorclaw mantris hynoid tuskor seige cycloid garganoid terrorclaw mantris hynoid tuskor seige cycloid garganoid