Who wins?
Cow vs Ender Dragon
Ender Dragon wins 77% to 23%. 23 more put them in the same row. From Minecraft Mobs Tier List. Pick a side.
TinyFalcon on Cow: the most useful mob early game, leather for books and steak that keeps you fed
HumbleMoose3788 on Ender Dragon: the final boss, with the end crystals and the bed strategy for speedruns
Minecraft Mobs Tier List: the full ranking