Thunder drakes are a special classification of draconic creatures. Believed to be descended from some of the first chromatic blue guard drakes, thunder drakes are quick adapters that have diverged into a few different species, all of which have something unique. 

Shoreclamper thunder drakes are extremely similar to common thunder drakes, to the point where many people have mistaken them for aquatic common thunder drakes at first glance. It turns out that shoreclampers are a special subspecies of the common thunder drake that has adapted to live in water and feast on hard-shelled crustaceans, including giant clams. Due the the giant clam's habit of making pearls and may other treasures being found deep beneath the cold waves, shoreclampers have some of the largest treasure hoards and largest sense of ego & greed among thunder drakes. They also have the strange magical ability to change the shape of their teeth from blunt to sharp at will. This allows them to be able to attack and kill coastal, mostly non-aquatic creatures that a blunt-fanged creature would normally have a challenge catching and eating/killing, such as marine iguanas. Another strange & unique thing about shoreclampers is what happens after the kill and eat a large hermit crab. The drake's blunt teeth smash through and shatter the shell, but in the drake's hunger, it swallows both the crab and the bits of shell whole. Often, the drake will regurgitate a few of the shell pieces. However, the pieces will not only be covered in an acidic substance for a few hours after their regurgitated, but also glow with a platinum colored shine. Though shoreclampers eat hermit crabs almost every day, the instances of the drakes regurgitating any amount of super-acidic shell pieces is incredibly rare. 

Any creature that touches a piece must succeed on a DC 16 Constitution saving throw or take 4 (1d8) acid damage & 1 lightning damage on a fail, or half as much on a success. 1d6 hours after the pieces have been regurgitated, they lose their super-acidic properties and become super-tiny pieces of material that are worth 3 pp each. 

Due to their somewhat greedy & egotistical personalities, shoreclampers end up amassing treasure hoards far larger than those of their less intelligent relatives, which only rarely hoard treasure. They often keep their treasure hoards protected in a secret area within their massive underwater lair of strangely-dug tunnels.

The treasure hoard of an young shoreclamper thunder drake, on average, contains around 140 (4d6 x 10) cp, 70 (2d6 x 10) sp, 170 (5d6 x 10) gp, 14 (4d6) pp, 5 (2d4) mundane items, 9 (2d8) gems (gems of 10-50 gp, but 50% white pearls), 3 (1d6) uncommon magic items, 2 (1d4) rare magic items.  Mundane items found in a shoreclamp thunder drake's hoard are usually less fantastical ones that were salvaged from shipwrecks or carriages or caravans that the drak attacked and destroyed.