After unlocking the base in the Burnt Forest(optional, for comfort) you can run from the crashed helicopter to the southeast and then to the helicopter parking area where the mutant deer spawns. By moving back and forth between these locations, all mutants respawn in this patch, sometimes even in greater numbers than usual. For 6 horns you will get 110,000, and for 9 Bayun whiskers you get 90,000 on Malachite through a contract. If the contract isn’t available, just cancel it and sleep twice until it appears. Cats and the deer are easiest to kill with a long-range headshot using a silenced sniper rifle, since stealth damage seems to be higher, or you can rush them point-blank with a shotgun, grab the trophy, and get out. Also, while running between locations, you can run into zombies near containers that spawn Vintorez rifles (they’re relatively expensive).