Enable Classic Mob Models and Shapes
Why Mobs Look Wrong
By default, mobs in modern Minecraft use updated models that don't match the Beta 1.7.3 style. The Default Beta Resource Pack includes classic mob shapes, but they won't display without additional mods.
Required Setup
You need either OptiFine or a custom entity model mod (such as Entity Model Features) installed alongside the resource pack. These mods allow the game to load the old mob geometry that comes with the pack.
1. Install your chosen mod (OptiFine is the most straightforward option)
2. Launch Minecraft with the mod active
3. Load a world with the Default Beta Resource Pack enabled
4. Mobs should now display with their classic blocky shapes—cows with their original proportions, zombies with the pre-1.14 design, and skeletons holding bows like regular items
Verify It's Working
Look for a skeleton in a dark area. If it's holding a bow as a regular item rather than in a combat pose, the classic models are active. Cows should appear noticeably more angular than modern versions.
Without this setup, you'll see modern mob models with the pack's textures applied, which breaks the authentic Beta experience.