They are portrayed by Oliver Platt & Stanley Tucci respectively
Harvey and Vernon are first seen in the opening in Dr. Herman Varnick's lab, carrying a cage. Harvey and Vernon then proceed stealing puppies from The Pet shop but stop short when Harvey accidentally steps in the beam forcing the two to run for it. One of the puppies, a St. Bernard puppy outwits them and escapes their van and finds the Newton family.
Later Harvey & Vernon capture Sparky the Jackrussel terrier who helped Beethoven escape their van.
Once Varnick gets a hold of Beethoven, he had Harvey and Vernon take the St. Bernard to the testing area. Later before the climax, Varnick orders them to bring Beethoven for the ammo test and "bring me a little one for this chemical test." Vernon decides to use Sparky the Jack Russell for the chemical test. After subduing Beethoven, Varnick prepares to shoot at him but George smashes into the area. When Varnick is sedated by Ted driving the van into the wall, Vernon and Harvey try to Make a run for it. Ted orders the dogs to "sick em" and the chase is on. Eventually, Harvey & Vernon reach a junkyard gate and climb over it and taunting Beethoven and the other dogs, only to discover four vicious dobermans on the other side as the dobermans attack them.Harvey & Vernon are last seen in bandages as they're being arrested along with their boss.