In the first chapter of Lego Batman: Legacy of the Dark Knight, the "Red Hood Gang" mission holds a hidden red brick that unlocks the "Toxic Waste" modifier. This guide provides the exact location of the red brick and instructions on how to collect it to enhance your gameplay.
Navigate to the area after the initial fight with Red Hood's henchmen. Look for a destructible wall near the stack of crates on the left side. Use a character with explosive abilities (like Batman or Robin with their explosive gel) to blast open the wall. Inside, you'll find the red brick on a pedestal. Collect it to unlock the "Toxic Waste" modifier, which turns all LEGO studs into green toxic waste tokens, doubling their value.