Grewcica serves as the primary antagonist in "Rusty Angel," the first episode of the Battle Angel OVA. A former coliseum champion turned wanted criminal in Scrapyard City, he preys on women to consume their brains. His fearsome reputation and combat skill deter local bounty hunters. Operating with his partner Rasha, Grewcica ambushes Dr. Daisuke Ido during an attack. Alita intervenes, severing Grewcica's right arm and forcing his retreat into the sewers. Seeking enhanced capabilities, he commissions cybernetic upgrades from Chiren, gaining fingertip-mounted grind cutters. In the subsequent rematch, Grewcica kills a stray dog Alita befriended, provoking her into a fierce battle. Despite his enhancements, Alita defeats him by bisecting him.

The live-action film features Grewishka, a character based on Grewcica. As Nova's cyborg enforcer, he ambushes Dr. Ido and Alita, resulting in Alita severing his arm and compelling his retreat. Rebuilt with advanced weaponry by Chiren under Vector's orders, Grewishka later kills Alita's dog, triggering another confrontation. Alita destroys him using the Damascus Blade, bisecting him.

Grewishka's film design and role originate from the OVA's Grewcica, who himself combined the appearance of the manga character Makaku with Kinuba's fingertip grind cutters. The film's blade bisection references Grewcica's OVA demise.