Green’s Dictionary of Slang

Dennis the Menace n.

MDMA.

1997		S. Champion Disco Biscuits v: Doves, Playboys, Dollars, Apples, Swans, White Burgers, Brown Burgers [...] Dennis The Menaces, Rhubarb and Custards, White Callies, Pink Flamingoes, Snowballs, Kinder Eggs, Energizers, Hammer & Sickles, Disco Biscuits.
2000		N. Griffiths Grits 448: Evah ad a Dennis the Menace then?