Cthulhu was an ocean-going sort of critter, so if you ignore the fact that Innsmouth is just a teensy bit too far north to be tropical a themed tiki mug sounds like a perfect fit. Horror in Clay is there to make it happen for you.
The shop (which, incidentally, takes its name from the title of the first chapter of Call of Cthulhu) got its start when tiki-and-Lovecraft fan Jonathan Chaffin commissioned a Cthulhu tiki mug from sculptor Kristina Lucas Francis. Response to the mug was so positive that Chaffin decided to launch a Kickstarter campaign to produce a run for sale. That was so positive (the goal was $12,500 and it received nearly $80,000 from backers) that it spawned a whole shop.
They’ve recently finished up another Kickstarter for the Innsmouth Fogcutter, with an in-the-round design depicting a pretty tropical diver’s transformation into a Lovecraftian fishwoman. The mug also bears the logo of the fictional Gilman House Hotel, a nice touch.
The shop also carries a bunch of other great barware and accessories: Check out their Pickman’s Cove collection for tentacly swizzle sticks, jiggers, and bar spoons.
Their blog is a tad sparse–only 9 posts over the course of a year–but is worth a glance for a couple of posts discussing tropical drinks, including their recipe for their signature cocktail, “Cthulhu Waits Dreaming.” The amounts provided in the linked recipe are for a party-size 5 gallons; I did a little digging and found a much more reasonable single-serving recipe from an interview Chaffin did with Mr. Booze:
2 oz gold rum
dash of dark rum
1/2 oz brandy
1/4 tsp absinthe
1/2 oz cinnamon syrup*
1/2 oz orgeat syrup
2 oz grapefruit juice
juice of 1/2 small lemon
5 dashes Angostura bitters
Begin by rinsing your Cthulhu vessel with fresh seawater. If you happen to be trapped inland, you can use 1/2 tbs sea salt dissolved in a cup of water instead. Then, in a shaker, combine all the other ingredients over ice. Shake and strain into the Cthulhu vessel over crushed ice. Chant “Ph’nglui mglw’nafh Cthulhu R’lyeh wgah’nagl fhtagn” over the top before drinking. After a few of these, Cthulhu may well return.
*To make the cinnamon syrup: Crush 3 cinnamon sticks and place in a saucepan with 1 cup sugar and 1 cup water. Bring to a boil, stirring to dissolve sugar. Lower the heat and simmer for 2 minutes, then remove from heat and let steep for 2 hours. Strain and bottle. Keeps for a month in the fridge.
Bonus Link: When I went looking for the cocktail recipe I found the Call of Cthulhu, which isn’t the same recipe but it’s both tropical and highly decorative.