Keifer can take a large amount of damage, even from high powered weapons like the Semi-auto Shotgun or the Buffalo Rifle. It is advised to stock up on ammo before attempting the Rio del Lobo hunting grounds.
The name Keifer is most likely a reference to actor Kiefer Sutherland, who portrays the character Bob Wolverton in the film 1996 "Freeway". The plot of the film is largely based on the story of Little Red Riding Hood. Sutherland also plays Doc in Young Guns and Young Guns 2.