Those examples from It's Always Sunny are excellent examples of playing on the scale of 1-10 almost entirely at a 10 as that character had essentially evolved into a cat.
I loved those two different animal examples from the same actor! I also love how it shows the subtleties of utilizing animal traits. While the Sunny clip was almost totally animal, Bronson's characters were definitely heavily informed by animal traits!
All of these clips are excellent examples of the possibilities of incorporating animal traits!
Here is a link to the most recent Improv Tip by Paul Vaillancourt, one of the founders of iO West in L.A. and author of The Triangle of the Scene, one of my favorite books on Improv. He is a terrific performer and teacher, and his tips are always helpful - I highly recommend subscribing to his YouTube channel.
Also, here is a link to his Improv Tip from May 30, with guest tipper, Armando Diaz, Improv legend and creator of the long form Improv format officially known as The Armando Diaz Theatrical Experience and Hootenanny, which is more commonly referred to as The Armando and performed by our very own Cory Jenks and his awesome team every Friday night in The Soapbox...
Get your kicks from Tip 66! Here is a "Lost Episode" (Tip 66) from Paul Vaillancourt and guest, Dave Hill - those of us Improvisors who are sober can still benefit from "having a drink" (no alcohol required) and just hanging out with our teams!