Outfits is the best way to differentiate your Animal Jam from other players. By dressing wildly and in a fun (but not offensive) way, you can garner the admiration of many players in Animal Jam world.
So how do you obtain more outfits? First, you can go on many different missions to unlock some outfits. For instance, Ninja Mask is a cool costume you can put on your face and turn your animals instantly into a Ninja. Then you can eaves drop on the happenings in Jamaa Township without fear of getting detected for using cheats.
Next, it is obvious that non-members look very different from members. Because Animal Jam membership codes unlocks a whole new world, it is very desirable for non-members to seek code generators.
It may be possible to stack the codes by getting the plushies but that can be a long road. It is much easier to imply use the right membership code generator to accomplish the same goal.