As soon as you enter the sewers’ second area, use the nearby checkpoint station to save your game. Then start smashing your way along the ramp until you reach the area’s central platform. Once there, Killer Croc emerges from the waters below, and the battle begins!
Begin the battle by smashing all of the objects around the central platform. Build their bricks into a familiar Hazard Suit contraption for Robin. You need to fill it with 25 LEGO parts.
You may have discovered a few LEGO parts while navigating the sewers, but you need more to activate the contraption. Go right or left to find a spot where Batman can use his Sensor Suit to detect a button (there are two such spots). Once you reveal a button, tag to Robin and leap onto it to open up a trapdoor.
Whoa—Killer Croc bounds up from the trapdoor, along with a whole bunch of LEGO parts! Ignore Croc and hold the Attack button to suck in all of those LEGO parts. Repeat this on the other side of the area, using Batman’s senses to detect the button as you did before. Make Croc bound out of both trapdoors to find all of the parts you need! Killer Croc won’t emerge from the trapdoors if he’s already lurking around. Wait for him to leave (he dives underwater), remaining on the button until he pops up from the trapdoor.
Deposit 25 LEGO parts into the contraption, and it spits out a familiar cannon. Hop onto the cannon’s gunner seat and press the Attack button to fire a net at Killer Croc that pins him to the wall, bringing this level to a dramatic close.
