A giraffe can be seen locked inside a disc during the opening sequence of the Monster Rancher anime series and Monster Rancher 2. It is assumed that this is just a regular type of animal that was originally used in the genetic experiments that the Pendant tribe conducted to seal living beings inside the mystery discs.
The giraffe is also noted in the description for Mewkiri, so chances are that they inhabit the less arid parts of the desert.