How can we create someone’s head to collect their bounty?

Last night, we boarded a pirate ship to collect 500g for its captain’s head. The Paladin, being a clever Shield Master boy, shoved him off the edge of the ship for the giant sharks in the water to take care of. After we cleaned up the rest of the crew, we Polymorphed the Paladin to go get the corpse back.

Problem is, we only found the gem-riddled cloak and scimitar the captain was wielding, and bits of his body (a hand and a leg). The rest of him, the sharks got. We need his head to collect his bounty. What options do we have, as a level 13 party with a Vengeance Paladin, Necromancer Wizard, Storm Sorcerer, Samurai Fighter, and Shadow/Chain SorcLock?

We thought we could Resurrect the dude, kill him again, and voilá, we had his dead. But that is not very lucrative to do.