In Minecraft, a Warm Cow does not exist as a separate entity; cows in the game typically look the same regardless of the biome they inhabit. Cows in Minecraft have a distinctive appearance, characterized by their black and white, spotted bodies. Bulls are not a separate mob in Minecraft; instead, all cows are referred to as cows.
However, if you are referring to the appearance or behavior of animals in the game in different biomes or looking for a specific variant mod or texture pack that might introduce new types of cows, there could be some similarities drawn. In general gameplay, cows and bulls are not differentiated, and any cow will look like a typical cow in the game.