I have been playing D&D since 1989 , I play with DM's who have been playing since it first came out ... All creatures are playable creatures in a game of fantasy , sure some you wouldnt want to play like say an ooze or a jelly but I have played every thing from a Human to a Blue Slaad its not hard to do you just follow the basic rules of character creati🥃on add in racial bonuses and call it a day easy peasy