At last week's LAT I showed how to repurpose the TSM Biped leg for use as a rear Quadruped leg.
https://youtu.be/KC7gqOOuSTg
However, after animating with that arrangement a bit I recommend you use the real Quad leg. It is less finicky to pose in animal leg situations.
Most of the process remains the same...
you scale rotate and scale the bones into position the same way
you attach and weight CPs the same way
you test out your attachments and weighting in an Action the same way
However, at the outset you choose the Quadruped skeleton in TSM Builder.
The downside of the true Quad leg is that is has no FK option but that is rarely needed for animal legs. It also has no bone like the Biped's "IK Foot Target" that marks the heel of the foot but that can be added manually if needed.
It also doesn't have the intuitive names for the bones that the Biped leg has.
This pic shows the correspondence between the TSM Biped leg as I used it in our Cat example and the TSM Quad leg bones.
@Roger @ChuckGram @KingVidiot @Shelton