During the deferi patrol mission there was a breen capital ship sitting in the back in sensor but out of combat range. Naturally being the curious type I attacked it after finishing the mission part. It had an active squadren of fighters (Scorps) that respawned 2 more times before it didnt exist any longer. It had a gravity well also. I was wondering if any others seen this spawn?

Is it the really really really really BIG one? If so, I think there's an accolade for finding all of them in the Breen missions (and killing them, of course).

I could be wrong but I dont remember seeing any scorps till the vault opened up so it it new?

There is an accolade for Destroying the three Breen Capital Ships. It is called "Captial Punishment". There is a ship in each of the areas where you help the Defari. I have only seen the one at outpost three. I am not sure what the spawning rate is, but I wish they would increase it to 1 chance in three that it will appear, even if that particular ship has been defeated by the player.

I've done more Defari missions than I care to mention and I've only found two of them. The first one went down pretty easily, but the second one took me almost 20 minutes.

Your best chance at these is to catch the server as it comes up from an update. I haven't seen anything posting a spawn rate but they seem to be active post update quite a bit, which is when I got mine done

If you find them...make sure to keep track of them, and go engage them when you wrap up your mission.

If you are feeling really nice, tell your fleetf/friends that you have found one - they will like you for it.