Devil's venom
Devil's venom was a nickname coined by Soviet rocket scientists for a hypergolic liquid rocket fuel composed of a dangerous combination of red fuming nitric acid (RFNA) and unsymmetrical dimethylhydrazine (UDMH). Both propellants are extremely dangerous individually: nitric acid is highly corrosive and releases toxic nitrogen dioxide during reactions, or even simply while exposed to air in its highly concentrated "red fuming" form, typically used as rocket propellant.