This mod is part of The Vanilla Experience.
Snowballs Freeze Mobs is a minimalistic configurable mod which makes it so that hitting a mob with a snowball will result in it being frozen.
Configurable: ( how do I configure? )
freezeTimeMs (default = 5000, min 0, max 3600000): The amount of time in ms the mob hit will be frozen for.
An example with an ocelot: