1. Features
1.1. Multicellular and heterotrophic
1.2. Backbone and internal bone skeleton
2. Fish
2.1. Features
2.1.1. Oviparous
2.1.2. Have
2.1.2.1. Fings
2.1.2.2. Gills
2.1.2.3. Scales
2.2. Types
2.2.1. Bony fish
2.2.2. Cartilaginous fish
3. Amphibians
3.1. Features
3.1.1. Oviparous
3.1.2. Live
3.1.2.1. Underwater
3.1.2.1.1. Young
3.1.2.2. Land
3.1.2.2.1. Adult
3.2. Types
3.2.1. Anura
3.2.1.1. Frog
3.2.2. Urodela
3.2.2.1. Salamander
4. Reptiles
4.1. Features
4.1.1. A tail and 4 legs
4.1.2. Oviparous
4.1.3. Land animals
4.1.4. Covered in feathers
4.2. Types
4.2.1. Squamata
4.2.1.1. Scales and tongues
4.2.1.1.1. Lizard
4.2.2. Testudines
4.2.2.1. Shells
4.2.2.1.1. Tortoise
4.2.3. Crocodylia
4.2.3.1. Strong jaws and teeth
4.2.3.1.1. Crocodile
4.3. Exception
4.3.1. Snake haven’t legs
5. Mammals
5.1. Features
5.1.1. Viviparous
5.1.2. Covered in hair or fur
5.1.3. Breathe through lungs
5.1.4. They are land animals
5.2. Types
5.2.1. Placental mammals
5.2.1.1. Rabbit
5.2.2. Marsupial mammals
5.2.2.1. Kangaroo
5.2.3. Monotremes
5.2.3.1. Platypus
5.2.4. …
5.3. Exceptions
5.3.1. Bats have wings
5.3.2. Some have fins and tail (dolphin)
6. Birds
6.1. Features
6.1.1. Have
6.1.1.1. Wings
6.1.1.2. Hollow bones
6.1.1.3. Good eyesight
6.1.2. Oviparous
6.1.3. Covered in feathers
6.1.4. Breathe through lungs
6.1.5. They are land animals
6.2. Types
6.2.1. Flying birds
6.2.1.1. Colibri
6.2.2. Flightless bird
6.2.2.1. Pinguin