When you spawn a few foxes/rabbits in some mountain biome like Lofty Peaks and Snow Capped Peaks, it spawns normal variant ones, instead of their snow variants.
Step to Reproduce
1. Go to any new mountain biome that has snow peaks.
2. Get a Fox or a Rabbit Spawn Egg
3. Place the spawn egg to spawn the foxes/rabbits
--> It spawns the normal variant, not the snow variants