"Enemy Surveillance" is a series of side missions in Infamous 2.
Cole meets with a civilian who informs him of a corrupted swamp monster lurking around. Cole is tasked with chasing down the swamp monster, following it to his lair. Once he reaches the lair, he must take down a whole bunch of them, including a Ravager.
When chasing the swamp monster, you must not harm it until he reaches the lair, or the mission will fail. You must also make sure you don't lose him. Avoid the Militia that appear along the way. Once you reach the lair, you must take down several monsters, including a Ravager. Cole's grenades is pretty useful against the Ravager. Stay away from the group of monsters, and try utilizing your bolts instead of meleeing the monsters, as to avoid being hit too much.