This is an officially licensed Family Guy product.
T-shirt has image of Peter in 'rasta' colors with dread locks and a scruffy beard. This shirt is so authentic you can roll it up and smoke it (not really but it still looks cool).
Proof that Peter's on something: "Not so fast, Lois. A boat's a boat. But the mystery box could be anything. It could even be a boat. You know how much we wanted one." - from Family Guy episode I Am Peter, Hear Me Roar