|Gregory's Unctuous Unction|
Makes the drinker think the one who gave them the potion is their best friend 
Green smoke 
From the English Unctuous, an adjective meaning either "excessively smooth, suave or smug" and is synonymous with "smarmy" (and hence a clear reference to the creator). It can also mean "having an oily or soapy feel" or "of the nature of an unguent or ointment", probably referring to the texture of the potion. Unction is an English noun which can refer to one of the following three things: an ointment or salve, the act of anointing (especially as medical treatment or as religious rite, hence why "Extreme Unction" is a synonym for Last Rites) or something soothing - in this case, "Unction" probably refers to all three.
Behind the scenes
- Given the potion's etymology and its known effect, Gregory's Unctuous Unction may have an emotional side-effect similar to the Imperius Curse (whereby the victim is placed in a sort of euphoric stupor).
- Harry Potter and the Philosopher's Stone (video game) (Mentioned on a Famous Wizard Card)
- Harry Potter and the Chamber of Secrets (video game) (Mentioned on a Famous Wizard Card)