Blue (Lupin House) - (free) Maya Animation Rig

 Blue is a free Maya rig available at Lupin House.

Retro (ProRigs) - (paid) Maya Animation Rig

 Retro is a paid Maya animation rig available at ProRigs.

Monkey (ProRigs) - (paid) Maya Animation Rig

 Monkey is a paid Maya animation rig available at ProRigs.

Jadd (Long Winter Studios) - (paid) Maya Animation Rig

 Jadd is a paid Maya animation rig available here.

Vixen - (paid Maya Animation Rig)

 Vixen is a paid Maya animation rig available here.

Aisha (paid Maya Rig)

 Aisha is a paid Maya animation rig available here.

Knight Spider (free Maya Rig)

Knight Spider is a free Maya animation rig by The Rookies available here, which is part of a contest you can read about here.

ToyRig (paid Maya Rig)

Get 10% off using the code: JDH101YR

ToyRig is a paid Maya animation by Animawarriors rig available here. Included is also the Dolly rig.

Harlow (paid Maya Rig)

 Harlow is a paid Maya animation rig by "Built by Colossus" and available here.

Stewart (paid Maya Rig)

Stewart is a paid Maya animation rig and available here.

Healthbot (Free Maya Rig)

 Healthbot is a free Maya animation rig and available here.

Artemis (Paid Maya Rig)

Artemis is a paid Maya animation rig and available here.

Sheik X Overwatch (Free Maya Rig)

Sheik X Overwatch is a free Maya animation rig and available here.

Skaarj

More info here.

Circuit Hero

More info here.

Wyrm Girl

More info here.

Samus Aran

More info here.

Reptilian

More info here.

Safiro

More info here.

Megalodon

More info here.