The Viper Probe Droid is likely to be your last scan for the Intergalactic Geographic: Scan every type of enemy to fill out the Tactical Guide Trophy. For many players, myself included, you did not pick this up during the story and/or the enemy seems to be glitched and you cannot scan the enemy by normal means.

If you missed the Viper Probe Droid (Koboh > Alignment Control Center) as you head to the Arrays as part of Chapter 6 during the story, do not fret. There is one more spawn location post-story and you will need to scan the enemy with unconventional means (manually). If you have not scanned it during the story, or find it is glitched, head to Nova Garon > Central Command.

From the Mantis, turn to the first door you unlocked (where the electric blue thing is you need to hit with darts). In that corridor at the end (directly ahead of you) is a lift. Take it down and then once you are down, walk forward a few steps and turn 90 degrees right and you will see a door/corridor next to some consoles. This is where you need to go BUT DO NOT ENTER YET.

The Viper Probe Droid is in this area a few feet to the right just through the door and hovering slightly off to the right in front of you as you go through. Walk very slowly through the door until you can see it. DO NOT LET ANY ENEMIES SEE YOU. Once you have it in sight hovering to the right, press down on your D-Pad to bring up BD1's scanner and then press the right thumb stick down so you enter the tagging mode. Now hover the cursor over the enemy so you can manually scan the droid. It should say this is an unknown enemy type and begin scan.

That should be your last and final enemy!