Is frog urine poisonous

No, some frogs are not poisonous and yes, some frogs are poisonous.

Specifically, some frogs can secrete bufotoxins which target a potential predator's or prey's nervous tissue. The toxic substance may be found stored in the skin on the anuran's back, neck and shoulders. It will be far more commonly found in salamanders and toads than in frogs (Dendrobatoidea superfamily).