You can find the specific ArtemisLib-1.12.2-v1.0.6.jar file on CurseForge. It was released on July 15, 2019, and is approximately 20.82 KB in size.
ArtemisLib. ... A modding library that lets modders resize entities without coremodding. CurseForge ArtemisLib - Minecraft Mods - CurseForge artemislib 1.0.6 download
It adds two primary attributes, ENTITY_HEIGHT and ENTITY_WIDTH , which can be utilized by modders just like standard Minecraft entity attributes. You can find the specific ArtemisLib-1
While version 1.0.6 is built for Minecraft 1.12.2, ArtemisLib is used by popular mods like Icarus and Arcanus in newer versions of the game. Installation Guide ENTITY_HEIGHT and ENTITY_WIDTH