Middle names for Atlas and Gracie?

This one's a little bit different lol! It's for my cat and dog! None of my other pets have middle names but I feel like these two need it when they are in trouble or not listening lol. With my other pets, I can put enough "umph" behind their name so they know they are misbehaving, or they have a nickname that works for that. But I feel like these two I can't do that with, so I think they need middle names lol. Atlas is a cat and we picked him up on the side of the road last year. He's suuuuper sweet and snuggly, but he still has that feral bit in him and does a lot of misbehaves lol he's been hard to train. Gracie is our 80-90ish lb dog. She is SO over the top sweet, but she has a sassy side and will straight up ignore you when you try to tell her to do something/ stop doing something. I've been using Lynn or Lou, because those were just the first two that came to mind with the name Gracie, but wondering if there is a better option that gives a good "umph" lol