Given the question: Who prevents Abu from being put down?  Answer the above question based on the context below:  The movie begins with a scooter chase between Harry and his nan because she didn't know it was him. Afterwards, Harry is sent to get a chicken for lunch, but they fire a machine gun at him and throw a grenade, which Harry throws into the chicken shed, blowing them up. Nan tells Harry the story of his twin brother, Otto, which Harry claims to have heard before.  Suddenly, Harry and Nan then discover that their beloved pet hamster Abu is ill after he vomits a green substance on them, so they take him to the vet. He is almost put down until Harry takes him back home. Ed the vet and his assistant, Kisko, are working for Harry's neo-Nazi twin brother Otto who was abandoned by Nan in the 1970s, claiming it was because she couldn't look after them both, and was raised by Alsatians. After another failed attempt to capture Abu (by disguising as a priest and a nun), Harry and Nan decide to take him on a trip in their Rover P6 to Blackpool for a week before he dies (when Abu really wanted to visit the home of Rihanna). Ed and his assistant pursue them on the road, until they arrive in "Blackpole" by mistake. The next day, Harry and Nan take Abu on a personal guided tour around the nuclear power plant by the cleaner. Ed and Kisko attempt to capture him again only for him to end up turned into a destructive giant caused by radiation which wears off shortly. While walking on the beach they encounter Barney Cull, a member of the Shell People.
The answer is:
Harry