Daniel Calf is a hallucination of Stan's, brought on by seizure medication that he takes to cover up the fact that he was texting-while-driving in "Seizures Suit Stanny".
When he tries to blame a second accident on Jeff Fischer when he wrecks the car trying to keep him from revealing the truth to Hayley, a doctor at the Hospital gives him a stronger dose of medication which causes him to hallucinate Daniel. Daniel tries to urge Stan to kill Jeff in order to keep the secret, but when Stan believes that Jeff is harmless, Daniel reminds him that Jeff's video evidence is still on the cellular company's mainframe and urges Stan to go destroy it.
At Daniel's urging to keep remembering "mainframe", Stan abandons his motor skills, and with a Frankenstein's monster-like countenance brought on by other side effects of the medication, goes on a rampage at Verizin' Wireless to destroy the mainframe, despite the clerks assurances that they only sell the phones and do not house the mainframe. Hayley calls to happily announce that Jeff has come out of his coma and Stan rushes back to the hospital to stop him, as Daniel reminds him that it was is idea to kill Jeff to stop him from talking to begin with.
Daniel is voiced by Kevin Bigley.