How do you walk on the toxic waste in Lego batman?

It seems you're referring to the Toxic Sewers level in Lego Batman: The Videogame. Here's how you navigate the toxic waste:

* Use Batarangs: You need to throw Batarangs at the glowing green toxic waste to solidify it, creating a pathway to walk on.

* Keep moving: The solidified waste will slowly melt back into liquid, so don't linger too long in one spot.

* Use the grappling hook: You can use Batman's grappling hook to swing over the toxic waste, avoiding the need to walk on it completely.

Let me know if you have any other questions about Lego Batman!