abs anthro athletic athletic_anthro athletic_male beak biceps bound clothing collar cuff_(restraint) deltoids feathers growth laboratory male muscle_growth muscular muscular_anthro muscular_male navel neck_muscles nipples panties pecs restraints ripped_muscles screaming solo test_subject thong triceps underwear veiny_muscles birdovo stolas_(helluva_boss) avian bird demon owl hi_res
Buff Stolas.

Looks like someone decided to train Stolas' body to the limit, with the help of magic or science :D