I remember that there are existing mods like "Better Nether," "Tinkers' Construct," and "Create," but morphing mods include ones like "Mob Morph" where players can turn into mobs. Could thisaddon be a version of Mob Morph by Skupkamcaddon? The name is different, though. Maybe it's a custom mod made by the developer Skupkamcaddon in 2021.