^^ Demerol is extremely toxic i believe, much more so than any other opioid/opiate. And it is rarely seen on the street. I've had a couple IV's of it in the hospital and it provides an extremely nice rush, but somewhat chilling/cold in a strange way.
God: Ohmefentanyl (40,000 times as potent as morphine) (i usually IV this 2-3x daily)
King's Father: Opium (ancient, but still smoked today, rare as fuck tho)
The King: Morphine (warm, happy, beautiful and as JC said the original opioid since 1804! and the first to be IV'd [1853])
Queens: Heroin / Oyxcodone (the king is a mormon, H is great, cheap, strong but rare, so the king fucks oxy on a more regular basis)
Prince: Hydromorphone (strong, quick high, but kinda disappointing when it wears off so quickly, kinda a douchebag, like the prince)
Princess: Hydrocodone (hot [warm] as fuck, and could be great one day if sold without the goddamn APAP) [CWE's are annoying!!!]
Joker: Codeine (shitty, weak, short-lasting high, BUT is nice when mixed with morphine in PPT)
"Special Prince": Tramadol (wants to be prince, but is just a bit too lame)
The King's Plumber: Buprenorphine (fixes problems caused by the rest of the royal family, including the king as well)