A mod ships a broken animation
What it looks like in your log
Unable to parse animation: animation.creature.walk
What causes it
GeckoLib could not parse an animation file inside one of the mods. The mod keeps running; the animation just does not play.
How to fix it
Nothing on your side. It is a data bug in the mod that owns the animation; updating that mod fixes it when its author does.
Not sure this is your problem? Paste your log and Roastd will tell you which of these it actually matched, and what else it found.
Check your own log