I thought he'd only appeared in Unificiation?
He's only mentioned in Unification. The actual Mr. Mot appears only in Ensign Ro
talking politics with Picard, & in Schisms
where he nearly gets disemboweled by Worf for holding scissors too close, & is mentioned again in Starship Mine
when Picard pretends to be him
Another similar looking, unnamed Bolian Barber speaking part appeared in Data's Day
giving Geordi a debated cleanup on his haircut. Memory Alpha lists him by his script name, V'Sal. His appearance is before the 1st mention of Mot. So it's possible they were meant to be the same character