Instead of getting a slightly bigger head when wearing a player skull, this mod will visually replace the entire skin instead. This mod does not add a way to obtain player heads, but I recommend the Vanilla Tweaks Player Head Drops datapack for singleplayer/vanilla servers and Spigot/Paper has many options like Player Heads. For testing the vanilla give command /give @p player_head{SkullOwner:Username} 1 will always work to get and play around with any skin you want.
Since this mod is purely visual and fully clientside, it doesn't have to be installed on servers and works everywhere!
Support via 
or Github! The comments are not there to report bugs/crashes/get help.
