The petting zoo at Hiratsuka Integrated Park (総合公園, ) is the only one I've found in the Kanto region that has hamsters as well as the more common rabbits and guinea pigs.The petting zoo has rabbits,chickens,ducks,hamsters ,guinea pig,sheep and goats.Really, a full roster of animals.Admission is free,as the zoo is run by the municipality.Pony rides are also available at a cut-rate 100 yen. There is Yoyogi Pony Park in Sangubashi, though and it is free, so there is no reason to come all the way to Hiratsuka for pony rides. The Itabashi Children's Zoo near Ikebukuro and Himonya Park in Meguro offers pony rides as well - I guess Tokyo is just lousy with ponies even though you can't find a crate of hamsters to pet anywhere near the place.