Bettas usually attack scales, gills and tails and will respond if bitten by aggressive fin nippers like angel fish or red tail sharks, Dr. Tepper says. Goldfish and dwarf gourami should also be avoided, as well as fish that are larger than your betta or have similar fins.
Consider these fish and other aquatic animals to put with bettas:
Cory catfish
Neon and ember tetras
Ghost shrimp
African dwarf frogs
Guppies
Kuhli loaches
Hope This Helps! Have A Nice Day!!