This script works from minecraft 1.8 up to minecraft 1.16 and it doesn't require iDisguise or LibsDisguise!
You can disguise as the mob you want and remove it without having to disconnect !
Your disguise stay even if you disconnect !
Screenshots 1 2 3 | Old video to show that it works
There's even a gif
French Version | French Video about it

/disguise help : List all the commands (permission: self.disguise)
/disguise list : List all the mobs that can be used with your version (permission: self.disguise)
/disguise <Mob> : Disguise in a mob (permission: self.disguise) (example: /disguise Enderman)
/disguise <Mob> <Player> : Disguise a player in a mob (permission: other.disguise)
/undisguise : Remove your disguise (permission: self.undisguise)
/undisguise <Player> : Remove a player's disguise (permssion: other.undisguise)

• You can remove the player's name above his disguise
• You can customize the name of every mob
• There are other options, but you shouldn't modify them unless you know what you're doing

• You need a recent version of Skript if possible (here for 1.8)
• ThatPacketAddon (for packets)
• Skript-Mirror or Skript-reflect (EntityId, pitch, yaw & packets)
• Latest stable version of ProtocolLib if you're in 1.11 or below or Latest 4.6 snapshot of ProtocolLib if you're in 1.12 or above (for packets) (you can still use the latest stable version of ProtocolLib in 1.15 or below if you wish to, but it's mandatory in 1.16)

Known bugs that can't be fixed
• The player will have the hitbox of the mob he is disguised as (with physical hit) (unfixable)
• Some mobs use pitch & yaw in a weird way such as Guardians
•Enderdragons face the wrong direction
• Shulkers don't move (They can't move in vanilla)
• In 1.9 & 1.10, rightclicking on a villager will make you crash and in 1.8 it makes the disguise invisible (for you only)
• Bats look afk, but doing a metadata customization would be too long
• NPCs are hidden with Citizens2. I can't fix it, just listening to a packet make this (even if I don't modify it)
• You'll have some errors when you reload the script if you don't have ProtocolLib 4.6 (We just need to wait for it to be stable and this will be fixed)

You can use functions in order to avoid 'make console execute..' and to disguise some players for other players. See more here (ugly but readable) or read the code

• Rush²Fer for helping me giving a name to the entities in 1.13 and above, ThatPacketAddon not working with optionnal chat
• Anarchick for helping me to update the stuff of the player in 1.16
• CarloDrift for giving me ideas and helping me test this

If you find any bugs, any typos or need help, send me a message here or on Discord (Phe0X#5907) but don't use reviews for that
If you like DisguiseMe, you can rate it !
PS: Sorry if my English is not perfect :/
I won't be really active anymore, read this for more information​