Primate

So, they took Cujo, moved it to Hawaii, populated it with vapid Gen Z'er stereotypes instead of a mom and her kid, set in a palatial estate instead of a car in a rural driveway, and traded the car for a pool but gave the kids multiple opportunities to get out of the pool. And turned rabies into a super-virus that causes total infection in less than two days, and can make a chimpanzee sadistic, malevolent, and calculating. Oh, and with no explanation whatsoever, have rabies show up in Hawaii, a place where it does not exist thanks to geographic isolation and rigorous screening policies. And have a script that depends on everyone making the dumbest decision possible because the plot can't happen naturally. Practical effects were cool, though.