Here is the full list of all 14 Clawfish achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Get on the train
Release all the fish in buckets
Catch all the fish in the Clawfish machines
Release all the fish in the Colorful Coral Clawfish machine
Catch fifteen fish from the Clawfish machines
Release all the fish in the Wild Wetland Clawfish machine
Catch ten fish from the Clawfish machines
Skip a stone
Sit on a bench
Get in the paddle boat
Purchase a drink from the vending machine
Release a fish from a bucket
Release all the fish in the Lucky Lakes Clawfish machine
Catch a fish from a Clawfish machine