Serratus anterior

>tfw small serratus muscles

What are good exercises for these?

dumbbell pullover

Push Ups

these

literally anything that moves your chest
>breathing heavy

fork put-downs (its a bodyfat thing)

sideplank reacharounds or reachthroughs or however you wanna call them

that would be bench press

Scapular protraction movements. This includes push ups, dips, and landmine press variations.

You're most likely not even lean enough to clearly see it so don't mind it

I've found that The Press and isometric shoulder exercises are good for developing this muscle, from my experience.