The Monster Costume is a retired costume that is a container of Kryptonite and was a part of the March 2014 Account Upgrade. Putting this costume on certain marapets will turn it into a mutated monster! Monster pets are black, green, and blue, perhaps coming from the Monster energy drink. They each have yokai-like features such as having a fire mane, mouths where they shouldn't, tentacles, spiked-up hair, dragon wings, fangs, and antennae.
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