What's the adjective for beefers? Here's the word you're looking for.
Included below are past participle and present participle forms for the
verbs beef and beef up which may be used as adjectives within certain contexts.
“Its small size and beefier caliber make it ideal for carry in a purse, pouch or ankle holster.”
“Shortly after this a man was marched back into the store and put into a small staff only room, guarded by a security guard and one of the beefier shop boys.”
“John's issue page seemed a bit beefier than George's bit about his agenda.”