This was a tourist piece from Butlin's Beachcomber bars that existed within British resorts back in the 60's/70's. I don't think they were used in the bars - just sold.
Distinguishing Characteristics
Bulins Beachcomber Mug - UK
Collector Gallery
Tiki Mug Design
Butlin's Beachcomber Mug
in 14 collections
This tiki mug was sold as a souvenir item at Butlin's Beachcomber restaurants, which had several locations at Butlin's family vacation spots throughout England. The mug is brown and has a handle on the side, and almost-demonic looking tiki face is painted in white and black.