There are 4 different disguise commands provided in the plugin. They differ in what gets disguised.

In addition, there are 4 different types of disguises which you can input using the disguise commands. Each of the types is available in every command.
Here are the 4 types:

Mob Disguise

You are now disguising as a cow.

Available mobs:

You can usually customize it with extra parameters (see below).

Player Disguise

You have constructed a player disguise which is called libraryaddict. You will show up with that name and skin.
&-color codes are accepted.

Use quotation marks " to put a space in the name, if you want to use multiple spaces in a row, to bypass the command limits that trims those spaces, escape the spaces with a backslash.

Example: /d player "The Green Apple"
Example: /d player "The \ Green \ Apple"

Misc Disguise

You are now disguised as a falling block, default uses the id stone.

Available misc disguises:

Note that these disguises, in general, are more prone to instability. Currently, you may not disguise as an item frame.

Alias Disguise

This command will take whatever libraryaddict is disguised as and apply it to you. (You need the 'libsdisguises.disguise.disguiseclone' permission to do this.)

Primary Disguise Options

Almost every disguise has options to customize or change it in some way.

For mob disguises:

You can set whether the mob is a baby or adult. This may not work with all disguises.

For the falling block disguise, provide 1 or 2 numbers. The first number is the block ID, and the second number is the block data. For example:

You are now disguised as birch planks.

For the 'painting' and 'splash_potion' disguises, you can also provide a number (art ID and raw potion damage value), but using the long form, detailed in the next section, is recommended.

Extra Disguise Options

You can set additional options on the disguises to do more stuff on them.

View the options using /disguisehelp <disguisetype>.
You can also view more information on types using /disguisehelp

The option types are

Number - A whole number. Examples: 5, 100, -32
Decimal - A decimal number. Examples: 5, 103.15, -78.6
String - A string. Examples: foo, bAr, hello
True/False - True or false.
Item - An item ID, and maybe damage. Examples: 46, 5:1, 32:13
AnimalColor - A wool color. Run /dhelp AnimalColors for valid values.
PotionEffect - The id or name of a potion effect. Run /dhelp PotionEffect for valid values.
HorseColor - The color of a horse disguise. Run /dhelp HorseColors for valid values.
HorseStyle - The style of a horse disguise. Run /dhelp HorseStyles for valid values.
Ocelot type - The ocelot type. Run /dhelp OcelotTypes for valid values.
Painting art - Which painting to show. Run /dhelp Art for valid values.
Villager Profession - The type of villager (their clothing color). Run /dhelp Professions for valid values.

Examples:

Note that there is a permission for every extra setting you can add. The permission node is the base permission for the command, followed by the disguise name, followed by the "parameter name" (e.g. setPowered), in all lowercase. Example: libsdisguises.disguiseradius.creeper.setpowered .

Command /disguise(top)

This command will disguise yourself.
Permission node base: "libsdisguises.disguise.*"
(Remember, "libsdisguises.disguise.*" will allow all disguises on yourself, and "libsdisguises.disguise.<disguise>.*" will allow all options for that disguise on yourself. This is the same for all 4 commands - just the 'disguise' part changes.)

The command aliases are /dis and /d.

Command usage: /disguise <disguise string>
See above for examples of what a disguise string is.

Command /disguiseentity(top)

This command will disguise the next entity you right-click (within the next 10 seconds) to the disguise you specify.
Permission node base: "libsdisguises.disguiseentity.*"

The command aliases are /dentity and /disentity.

Command usage: /disguiseentity <disguise string>

Command /disguiseplayer(top)

This command will disguise another player. They are not notified.
Permission node base: "libsdisguises.disguiseplayer.*"

The command aliases are /dplayer and /displayer.

Command usage: /disguiseplayer <other player> <disguise string>
Again, see above for examples of what a disguise string is.

Command /disguiseradius(top)

This command will disguise all entities in the specified radius around you to the same disguise.
Permission node base: "libsdisguises.disguiseradius.*"

The command aliases are /dradius and /disradius.

Command usage: /disguiseradius <radius (blocks)> <disguise string>
Again, see above for examples of what a disguise string is.

Command Undisguise(top)

Use this to slip out of your clingy disguise!

Permission: "libsdisguises.undisguise"

The command aliases are /u and /undis

Command usage: /undisguise

Command UndisguiseEntity(top)

Use this to undisguise the next entity you right click!

Permission: "libsdisguises.undisguiseentity"

The command aliases are /undisentity and /undentity

Command usage: /undisguiseentity

Command UndisguisePlayer(top)

Use this to undisguise the player of your choosing!

Permission: "libsdisguises.undisguiseplayer"

The command aliases are /undisplayer and /undplayer

Command usage: /undisguiseplayer <Playername>

Command UndisguiseRadius(top)

Use this to undisguise all entitys in a radius around you!

Permission: "libsdisguises.undisguiseradius"

The command aliases are /undisradius and /undradius

Command usage: /undisguiseradius <Radius Size>

Command DisguiseViewSelf(top)

Use this to toggle the disguise model that appears when you disguise.

Permission: "libsdisguises.seecmd.viewself"

Aliases: dviewself, dvs, disguisevs, disvs, vsd, viewselfdisguise, viewselfd

Command usage: /disguiseviewself

Command LibsDisguises(top)

Use this to reload libsdisguises and other helpful functions

Command usage: /libsdisguises reload / scoreboard / permtest / json / metainfo / config / mods / count / update

Command DisguiseHelp(top)

Use this to fetch more information on constructing a disguise.

You need the permission to use at least one disguise.

Command aliases are /dishelp and /dhelp

Command usage: /disguisehelp <DisguiseType>
Command usage: /disguisehelp AnimalColor
Command usage: /disguisehelp HorseColor
Command usage: /disguisehelp HorseStyle
Command usage: /disguisehelp OcelotType
Command usage: /disguisehelp Profession
Command usage: /disguisehelp PotionEffect

Command CopyDisguise(top)

Use this to output a disguise to string, this string is usable in a /disguise command.
If used on a player disguise, two messages will be sent with the skin data, and without.

You need the permission: libsdisguises.copydisguise

Command aliases are: /disguisecopy, /disgcopy, /dcopy, /copydisg and copyd

Command Usage: /copydisguise
Command Usage: /copydisguise <Player Name or UUID>

Command GrabSkin(top)

Use this to upload a skin from a file, from an url or from an existing player name or uuid.
This will download the skin and save it as a file, as well as provide the skin data in a message.
If uploaded from a file, the file must have a .png extension and be located in your "skins" folder of the Libs Disguises plugin folder.

The plugin will generate a name automatically if possible, or save as 'Skin1' etc.
You can also define a name to save as by adding it as a second parameter.

If you want the slim Alex model version of a slim, add :slim to your skin information. Such as myskin.png:slim

You need the permission: libsdisguises.grabskin

Command aliases are: /uploadskin and /skin

Command Usage: /grabskin https://www.site.com/notch.png
Command Usage: /grabskin notch.png
Command Usage: /grabskin notch.png:slim
Command Usage: /grabskin Notch
Command Usage: /grabskin a149f81b-f784-4f89-87c5-54afdd4db533
Command Usage: /grabskin <Parameter> <Name to Save As>

Command Save Disguise(top)

This lets you save a disguise as a custom disgiuse in the disguises.yml provided by Lib's Disguises.
This means you can then in the future reference this disguise by name, such as /disguise IncrediblyComplexDisguise or in Mythic Mobs.

The first argument is the disguise name, the following is the disguise data. If doing a player disguise, the plugin will attempt to set skin data on 'setSkin'. So if absent, 'setSkin' will be added with skin data, if present. The skin name will be parsed and parsed into skin data if possible.

You will never get a skinless disguise saved if all goes well. This is to increase performance and stability for keeping skins the same.

If you want the slim Alex model version of a slim, add :slim to your skin information. Such as myskin.png:slim

You need the permission: libsdisguises.savedisguise

Command aliases are: /customdisguise, /createdisguise, /createdisg, /savedisg and /customdisg
For reference, "Notch" is a player name. You can make it "Dinnerbone", or "libraryaddict" or "DemonSlayer9000" if you want.

Command Usage: /savedisguise DisguiseName <Disguise Data>
Command Usage: /savedisguise BabyCow cow setbaby
Command Usage: /savedisguise Notch player Notch setglowing
Command Usage: /savedisguise Notch player Notch setglowing
Command Usage: /savedisguise Notch player Notch setSkin herobrine.png
Command Usage: /savedisguise Notch player Notch setSkin herobrine.png:slim
Command Usage: /savedisguise Notch player Notch setglowing setSkin Herobrine
Command Usage: /savedisguise Notch player Notch setglowing setSkin a149f81b-f784-4f89-87c5-54afdd4db533
Command Usage: /savedisguise Notch player Notch setglowing setSkin https://www.site.com/herobrine.png

Placeholders(top)

Placeholders are used to replace stuff in the disguise string as its provided. This is not compatibility support for PlaceHolderAPI.

There are three versions of each placeholder you can use. The normal version. A version with a player name, and a version with target provided.

The normal version uses the command sender for its placeholder replacements.
The player name uses that player if online for the placeholder replacements.
The target uses the entity being used for the disguise, for the placeholder replacements.

%name%
%displayname%
%skin% - Only valid if entity used for placeholders is a player
%held-item%
%offhand-item%
%armor%
%helmet%
%chestplate%
%leggings%
%boots%

If using a target. Then just prepend 'target-'
So %held-item% turns into %target-held-item%

The same for players.

%libraryaddict-held-item%

Possible Mob Disguises are: (Additional mobs probably work as well if they are unlisted)