Don't know about terraria specifically, but it's a sliding scale of how you like beef cooked right?

The mid section is the usual meat doneness from Well done to Rare

Going up it parodies loot rarity types from Rare to Mythic (maybe Unreal is one too?). The idea is that, going "more rare" than rare beef is

• Rare - Rare beef
• Epic - raw beef
• Legendary - Live cow
• Mythic - All the ancestral cow-like creatures that evolved into cow
• Unreal - The primordial ancestor of all life on land