The English translation of the (Dutch) "strandbeest" is "beach animal".
One place where you might possibly have heard "strand" meaning the beach: Lewis Carroll. "The Walrus and the Carpenter were walking on the strand: / They wept like anything to see / Such quantities of sand. / 'If this were only cleared away,' / They said, 'it would be grand.'"
So I guess I'd offer "beach critter"?
* https://www.partyfortheanimals.com/en/organizations/partij-v...