Although this article is based on official information from the Star Wars Legends continuity, the actual name of this subject is pure conjecture.
A platypus was a peaceful creature that resided in Zarrak's mountain. It had the bill of a duck and the shell of a turtle. Zarrak, a user of dark magics was able to transform this creature into a much larger and fearsome form using his powers. He did this to show his apprentice, Teebo how to transform creatures into aggressive animals. However, when Teebo attempted to transform the beast, he accidentally transformed stranglevines instead, and the platypus swam away.
Warning: The following section is non-canon within the Star Wars Legends continuity. It contains information explicitly released under the Infinities brand and/or confirmed to be non-canon by the author or Lucasfilm. Information exclusive to this section did not happen in the "proper" Star Wars Legends continuity.