What are examples of animal imagery in Othello, and what is their purpose in the drama?

In
August of 1600, an Ambassador from the court of Barbary, Abd el-Ouahed ben Messaoud, arrived at
the court of Queen Elizabeth I. He stayed in London for six months, during which time he met
with the Queen on more than one occasion and was, according to contemporary accounts, the talk
of London.

Three plays were performed at court by Shakespeare's company, the
Lord Chamberlain's Men, during the time Abd el-Ouahed was in London. Shakespeare's company was
occasionally called to court to perform for visiting dignitaries. The acting company performed
at King James I's court for the Spanish ambassador in 1604, for example (at which time
and were performed), so it's possible that the
ambassador from the court of Barbary would have attended one or more performance by
Shakespeare's company during his own visit. If so, Shakespeare might have met, or at the very
least seen him there.

Othello was written in 1603 or
1604. There's very little doubt that Shakespeare modeled...