Ambient Killer is a daily achievement that requires you to kill 30 indiscriminate creatures. Indiscriminate creatures are wildlife such as rabbits, racoons, hawks, snow owls, ravens, rats, does, crabs, salmon and so on. They have names appearing in white, do not attack, have extremely low health to the point where they can be killed in one hit most of the time, take many times more damage than a regular foe, do not give exp and do no drop loot. The quickest way to get this achievement is to find an area with a high population of indiscriminate creatures with low respawn timers. There are two such areas which can be reached easily even with low level characters.
- Vale Waypoint in Queensdale: There is a ranch nearby this waypoint with a lot of chickens running around. If you go slightly south, you will encounter a small pool with coba salmon. There are does in the forest next to the pool. If you decide to venture further, follow the road to Claypool, which has a significant number of pigs, chickens and rats. All these creatures count toward the achievement.
- Horncall Waypoint in Wayfarer Foothills: Climb the stairs nearby the waypoint to the skill challenge. There is a large population of quick respawning raven all around the skill challenge. Since nearby ravens will take flight and land somewhere else if you kill a raven, it is advisable to use a ranged weapon to have an easier time of attacking these creatures.
Other than these two areas, generally most towns and farms have high populations of indiscriminate creatures. Note that you cannot attack indiscriminate creatures in cities since their names will appear in green.
The two areas mentioned above are also good places to farm indiscriminate creature kills for the Indiscriminate Slayer achievement (1000 indiscriminate kills). But most likely you will reach that amount by the time you reach level 80 provided you kill every indiscriminate creature you encounter while levelling, therefore it is not necessary to farm indiscriminate creatures unless you really want that achievement.