Custom player models
Anyone remember those custom model skin packs that you'd need some sort of edited version of minecraft to use? I managed to achieve something similar (if not originally the intention) without anything other than a resource pack! You won't have to worry about getting banned for it, as nobody but you can see your changed model. It even has (mostly) correct held item positions! Current models:
Lugia (Pokemon)
Gyaoon ([scrapped] Pokemon)
Wyvern (technically a terraria wyvern, however this one's a bit... stubby.)
Ashura (Sonic Boll/Boll Deluxe, tries to follow the official sonic skin pack style)
Slugcat (Rain world)
Missingno (My own design that I made, which is usually referred to as Vantark. it throws the glitchy stuff out the window at least in terms of design.)
Known Bugs:
Different resource packs that use player entity.json may mess this up, or if another pack changes the player model.
Known incompatibilities:
LA nature (causes the player to be invisible)