Possible Clues:

• Yellowstone grazers often approached by tourists
• Lower-fat hamburger meat
• Animal in some ancient cave art
• Big beast with Paddington, say, for a Londoner
• Big and beastly, one is in a snob
• Hairy bovine
• Shaggy-haired ox
• Large, wild shaggy-haired ox
• Beast is outwardly like a skeleton, for the most part
• Shaggy plains animaL