The phantom truck is a truck that likes to sneak up behind you while you drive on the highway and gets close to you and scares the shit out of you then you look away and try to get away from it then you look back and it's gone.
Driver: holy shit!!
*swerves to the right*
Passenger: dude what the hell?!?
Driver: that huge ass truck almost rammed into me!
Passenger: what truck?
Driver: it was just there a second ago!
Passenger: oh snap it was the Phantom Truck!