Hydrazine
Hydrazine is a family of chemicals that have found some use as rocket fuels.
The one most frequently referred-to is N2H4. It has an oxidation number of -2. It's a liquid with weak basic properties similar to ammonia. It can be made by oxidizing ammonia with sodium hypochlorite. It is a monopropellant.
The hydrazine used to make hypergolic (Self-igniting) bipropellant rocket fuels is usually unsymmetric dimethylhydrazine, a methyl salt of simple Hydrazine.