Duck PocketPal is one of the Cosmetic features on Minecraft Central. It was added in 7th May 2016 and belongs to the category PocketPals. It works everywhere on the server, except Minigames.
The only way to obtain this feature is by purchasing it separately from the webstore. The PocketPal can be enabled in Lobbies through the Cosmetic Menu and on other servers by doing /PocketPal.