An informant is the PHer and like with most nameds here, this PHer spawns in sets of 5. Interesting there are 2 sets of 2 which hang out together, presumably because an informant has to pass his information to... er, another informant? Take Teleporter C, follow the tunnels a bit and you'll stumble across all 5; of course, track helps.
Easily the hardest named to spawn. Have cleared 15x with no luck. Swordmaster was a pain too but she was up right after a patch.
Spawned after 23 clears. He's non-aggro to halfling druid. Was the rarest of the nameds in this zone for the Hunter Achievement. Also the last I needed. Sometimes I wonder if the game AI does this on purpose: reduces the spawn rate for a player clearing PHers who has all but one of the nameds already killed. Makes me wonder because this is not the first time this has happened. My approach in bindable zones is to focus my attention on 2-3 nameds at a time, bind near their spawn locations, port in, clear all the PHers, port out and kill time and then repeat. So the fact that in this zone the named I happen by chance to leave for the last has the lowest spawn rate (at least as experienced by me) makes me wonder if there's a mechanism at work here.
/ponder
Edited, Jul 3rd 2021 8:30am by Sippin