M Kat is a nickname for Mephedrone, also known as 4-methylmethcathinone (4-MMC), is a stimulant and entactogen drug of the phenethylamine, amphetamine, and cathinone chemical classes.

Mephedrone is reported as causing effects described as a cross between those of methamphetamine and MDMA ("Ecstasy"), producing euphoria, stimulation, and empathy. It generally sells for a higher price than MDMA but is cheap to produce meaning that manufacturers are making "huge amounts of money" from selling the drug
Man, I snorted a ton of M Kat last night, i was off my tits.
by MrDBamboo December 1, 2009
Get the M Kat mug.
nickname from George W. Bush for Mark McKinnon
M-Kat was chief media advisor to Dubya for his gubernatorial and presidential campaigns.
by Coop Dupe August 23, 2020
Get the M-Kat mug.