In the second Jurassic Park movie, a pack of tiny Compsognathus swarm Peter Stormare's character, Dieter Stark. Apparently, even the remote-controlled puppet versions of these Compies were vicious little critters; some were designed to actually bite Stormare's lip.
Stan Winston Studio posted this video of how they accomplished the Compy attack, and it's a great example of what practical effects can achieve. For one thing, there is the great, frenetic thrashing of the dinosaurs' tails, but Christian Colquhoun says that the real biting effect caused even the crew to cringe.
JURASSIC PARK 2: THE LOST WORLD - Compy Dinosaur Attack [Stan Winston Studio via The Mary Sue]