During the 1751 Carnival, a rhinoceros which was going by the name of "Clara" was being taken around Europe to be shown as a big attraction (no TV back then ...), was taken to Venice to be shown to the crowds.
Here's Clara's trip since 1741: Holland, Belgium, Germany, Switzerland, Austria, France, Italy and finally Venice.
By the end of 1751 Clara was in England, then Poland, Czechoslovakia, Denmark and finally passed out in London in 1758, with 20 years of age.
Pietro Longhi, the famous Venetian painter of that time was asked to make two paintings to commemorate the event.
On the side, Longhi's son, Alessandro, also wrote a little playful mocking rhyme about Clara:
"Il gran rinoceronte qui si vede
Dall’Affrica condotto in sto contorno
E della belva smisurata in fede
Del suo naso cornuto eccovi il corno."
"The great rhinoceros you see here,
Taken from Africa to this place
And of the big beast, to be true to you
From his horned nose, we show here the horn."
The Clara rhinoceros seems to have come from China (or India?) thanks to the Dutch Captain Douve Mout van der Meer on January 22, 1750.
The Venetian owner made a good business out of it, around 4.000 Ducati, it seems, but most of them were later left in the Venice Casino, Il Ridotto.
There is talk that there had been another rhino already in Venice, in the XIV century, with the Doge Andrea Dandolo, as we see documented on the mosaic in the S.Isidoro chapel.
But since there hasn’t been found any other marks in the chronicles of the time (and for such an event that would not have been likely to happen) historians regard this possibility as mostly speculation.
The S.Isidoro chapel mosaic was very likely an art-work depicting an imaginary unicorn-like animal used as symbolic decoration.
The tree of life behind him in the mosaic pushes very much in this direction.