This mug was issued by Black Lagoon as the "2025 Frown-der Mug" for their 5th anniversary Halloween cocktail experience. It features a matte grey wipe-away glaze and lime green eyes, and was available on location for $30 USD.
This mug is based on the "Angler" mug originally issued by Black Lagoon and Tiki Farm in 2016 in several colors, but this version has short dashes all around the eyes, nose and jawline, and a more metallic looking nose - as if it were a zombie/robot fish. There's no maker's mark or event name on the mug.