A coldblooded animal refers to an animal that cannot regulate its body temperature internally. Instead, it relies on the external environment to maintain its body temperature. Based on this definition, we can analyze each option provided.

Option 1: Pigeon - Pigeons are warm-blooded animals, meaning they can regulate their body temperature internally, so they are not coldblooded.

Option 2: Tortoise - Tortoises are coldblooded animals. They rely on the sun`s warmth to raise their body temperature. This makes them dependent on the external environment for temperature regulation. Therefore, this option is correct.

Option 3: Fox - Foxes are warm-blooded animals. Like pigeons, they can internally regulate their body temperature. Therefore, they are not coldblooded.

Option 4: Goat - Goats are also warm-blooded animals. They have the ability to regulate their body temperature internally. Therefore, goats are not coldblooded.

In conclusion, the correct answer is option 2, Tortoise.