Unlike some other unused models, the only evidence of the Panther are pictures. Most others unused enemies were still left in the game's pak file. I don't know much about them except they were very dog like creatures and that they may have been replaced by Hound Eyes.

panther.jpg (61596 bytes) A close up of a Panther

panther0.jpg (8910 bytes) A panther who caught a scientist

panther1.jpg (15009 bytes) Here you can see Barney throwing a scientist to the Panther

panther2.jpg (60796 bytes) A wireframe of the Panther, notice the cell it's being kept in

panther3.jpg (43214 bytes) In some pics the Panther is red for some reason