OK, I’m just guessing. Maybe I should say “secret agent frog.” Or maybe it’s not even a frog. When I first saw it, I thought it kind of tacky, then realized it had a constant flow of people having their photo taken with it , with the lovely river Solís Chico in the background. Good idea!
Update 20170202: “One of the most striking features of [Parque del Plata] is the monument to Sapo* Ruperto, character of children’s stories created by the Uruguayan writer Roy Berocay, who tells us from his work that his birthplace is precisely the stream Solís Chico. The person responsible for the sculpture was Nelson Capote and the monument was placed there within the framework of the 75th anniversary of Parque del Plata.” (source)
*Sapo means toad, and yes, he’s a detective.