Gain proficiency in Animal Handling, if you already have proficiency double your proficiency bonus.
Additionally, you may select a class of animals or to specialize in handling. You gain advantage in Animal Handling checks for species of that class and advantage on all Nature and History checks to recal information on species of that class. Classes to choose from include (centipedes and millipedes, spiders, scorpions, and kin, octopuses, squids and cuttlefish, crabs, lobsters, crayfish, krill, various shrimp, woodlice, and kin, cartilaginous fish: chimeras, sharks and rays, ray-finned fish, lobe-finned fish, amphibians, rodents, bats, hedgehogs, moles, and shrews, primates, whales, dolphins, and porpoises, herbivorous mammals, carnivorous mammals,birds, and reptiles)
This feature can be taken up to eight times each time for another class of animal at the same AXP cost each time. However, the proficiency bonus only doubles once.