### Instruction:
Choose the word which is different from the rest: Swan, Chicken, Crocodile, Frog, Snake.

### Response:
The options provided include multiple reptiles and birds. Reptiles are air-breathing, cold-blooded vertebrates that have scaly bodies rather than hair or feathers. Birds are warm-blooded egg-laying vertebrate distinguished by the possession of feathers, wings, and a beak. Since there are multiple reptiles and birds listed the answer lies in their habitat. The correct answer is chicken as all others listed can live in water.