Other Specials seem to spawn and instantly do their attack, with Packmasters and Gutter Runners spawning within 10ft.
Gas Rats seem a bit strong with it though. They spawn and instantly have an orb in the air before you can react.
On Athel Yenlui, we had one spawn inside our group on of the switches (within 5ft of us??) and instantly throw and orb at the floor.