1. Cow is a Herbivore animal , because cow eat grass, plant , hay and other plant products.
2.Tiger is a carnivore animal, because tiger eat meat of other animals.
3. Crow is a omnivore animal, because crow eat plant like nut, grains and fruits etc and crow also eat insect, reptiles and egg etc.
4.Dog are omnivore because dog eat grain and meat.
so, the answer is Cow.