Does Skeleton Physics Resource Pack work with other mobs, or just skeletons?

Just skeletons. The pack is specifically focused on skeletal mobs, so it won't change animations for zombies, creepers, or anything else.

Do I actually need OptiFine for this to work?

Yes. The physics animations rely on OptiFine's custom entity model support. Without it, the pack will load but the animations won't do anything different.

Will this pack hurt my FPS?

It shouldn't. The pack runs at 16x resolution, which is actually lighter than vanilla. The animation changes are minor and unlikely to cause any noticeable performance drop.

Can I use this alongside other resource packs?

Yes, as long as you stack them correctly in the Resource Packs menu. Put Skeleton Physics higher in the list if you want its skeleton textures to take priority over other packs.

Does this work with Fabric or Forge mods?

Resource packs don't depend on mod loaders. As long as you have OptiFine installed for your version, it works regardless of whether you're using Forge, Fabric, or vanilla.

Skeleton Physics Resource Pack (1.20.2, 1.19.4)

Skeletons in vanilla Minecraft move stiffly, like they’re attached to a rigid frame. This pack fixes that by adding physics-based animations to skeletal mobs, so they actually look like their bones are moving and reacting as they chase you down. It’s a small change that makes a noticeable difference, especially in combat.

What This Pack Does

The whole focus here is on skeleton mob animations. Instead of the usual locked, mechanical movement, skeletons now have more fluid motion when walking, strafing, and drawing their bows. Their limbs react more naturally to movement, which makes them feel genuinely unsettling in a way the default animations just don’t.

Key Changes

Physics-based bone movement for skeleton mobs
More realistic arm and leg animation when moving and attacking
Smoother bow-drawing animation
Works at 16x resolution, so performance impact is minimal

It’s a focused pack. It doesn’t touch every mob or overhaul the whole game, just skeletons. If you want the rest of your textures left alone, this is actually a good thing.

Requirements

OptiFine (required for the animations to work)

How to Install

Download and install OptiFine for your Minecraft version first.
Download the resource pack file below.
Open Minecraft and go to Options > Resource Packs.
Click Open Pack Folder.
Drop the downloaded .zip file into that folder.
Back in Minecraft, click the pack to activate it, then click Done.

Full guide here if you need it: How To Download & Install Resource Packs with OptiFine

More packs to check out: Minecraft Resource Packs