I have found these four locations in the southern area of the Ilum pvp group area. The Destroyer or Defender is at one of these locations. It also seems that the spawn system only allows one to be up at any given time in this southern area.
This should help those that want the L1-L Defender Pet!
Is the respawn timer for those ones 5-minutes like the PVP area one? I know last time I was hanging out farming them for the pet (didn't get it), it didn't seem to summon? But since I didn't know one of those locations it is possible I missed it. Any clue on respawn timer would be awesome.