Zangoose's name comes from the Japanese word for cutting or beheaded, 斬, zan and mongoose (mongoose).
In real life, snakes and mongooses are biological rivals. They're like the stereotypical Dog/Cat fights going on through the ages. Mongooses have also developed antibodies, and are immune to snake venom, which is seen through Zangoose's Dream world ability Toxic Boost, which gives him an advantage over Seviper.
And taken from another site: Zangoose is based on the mongoose, a cat-like carnivore that is well known for its ability to hunt and kill venomous snakes.
Sorry but facts are facts, Zangoose is a mongoose.