Mob varients based on biome

Some variants to minecraft mobs would provide some variety to the game. Minecraft earth variants would be interesting, but so would mobs similar to the stray and husk, but with passive mobs. For example, Hogs replacing Pigs in savannas. The only difference would be that they would have tusks and be neutral. Or Zebras replacing horses in savannas as well. Maybe even red pandas replacing foxes in jungles, only eating bamboo, not hunting.