This is a shot of a mutant that is standing guard near the coronal discharge thruster field repair station at Ellington Field near Houston. You can tell it is a mutant because of the enlarged cerebellum which obviously means superior intelligence. The creature is outlined by the glow from a coronal discharge thruster on the stand at Ellington Field. These creatures resemble what we earthlings refer to as dogs; hence, they are virtually indistinguishable from the creatures sometimes referred to as man's best friend. Personally, I think women are man's best friend, but what do I know.
These particular sentinals are quite clever. Although they are completely capable of walking on two feet, they never do so except in a circus. This is to perpertuate the ruse that it is a trick they can learn and not a normal mode of movement. That way, if we ever see a dog (wink wink) walking on two feet, we will naturally assume that it has been trained to do so by its master.