The hypothetical vehicle that's called for someone who is whining, usually in a self-absorbed and/or annoying way.
"I hate myself, and that person said mean things to me, and my milk got spilled, and my cake fell."
"Ugh, someone call the waahmbulance!"
Like an "ambulance" you would say your calling one of these when someone is being a total fucking pussy and whining.
Fool1: OMG THA TIS SO GHEY OMG!!!1111
Fool2: omg cry more fag lololol, im gonna call the waahmbulance