In a recent post on the FINAL FANTASY XI Official forums, community representative Camate posted an update about the announced “Play as a Monster” system that was announced back in April.
Players that decide to participate in this new content won’t have their player name displayed above their heads. Instead, a more generic monster name will be displayed instead. A “monster skill” option will be added to the menu which will allow you to select attacks that will require and consume TP. At certain levels, your monster will learn new abilities and eventually you’ll have the oppurtunity to upgrade into another monster (for example, going from a regular, brown Rarrib to a black or white one) and those will each have different abilities that they can learn.
Camate also revealed in his post that some of the data for this content has already gone onto the Test Sever! However, the Play as a Monster system isn’t available just yet. There will be more information on the overall system soon.