Four snakes including an 11ft (3m) boa constrictor were found by police during a callout to a suspected cannabis farm.
Two dogs were also discovered at the house in Doxford Walk, Hemlington, Middlesbrough.
The boa constrictor was found under hoardings and rubbish inside a substandard vivarium, Cleveland Police said.
The snakes, which were "stressed" because there was no electricity to keep them warm, were taken to safety.
The dogs were also rescued.
The smaller snakes were put in bags and the boa constrictor was kept inside its vivarium inside the back of the police van, police said.
PCSO Mark Ballinger said: "It wasn't an easy task as handling snakes isn't something we're prepared for or used to.
"We got a shock when we saw the animals, but knew that we had to save them and take them to the vets."