This is the smallest puffer fish in the world! Really, really small, no kidding! Actually, full grown they are just about the size of a penny...maybe! Not to be confused with aggressive Figure 8 Puffers or Green Spotted Puffers you might see at the pet store or all of the know-it-all's on the internet forums claiming these are aggressive. These are peaceful, and very beneficial in the aquarium as they eat small (we mean small) snails, mosquito and dragonfly larvae, and other aquatic bugs like mantis shrimp and plant leeches and other micro organisms. Remember, these are a schooling fish. KEEP THEM IN GROUPS, BIG GROUPS! Perhaps the people that have had aggressive dwarf puffers kept them secluded without any buddies, or maybe they had only a pair, where they were only defending themselves or their eggs. Other instances of fin-nipping might occur due to improper water parameters, lack of territorial borders, or a lack of quantity!!