I'm not sure why the puffer makes the list. You can play with them all you want and not get poisoned, you'd have to consume it. They do have a beak they can nip you with and remove flesh.
Puffers are fun to keep, they recognize you as the food source and often pace at the glass waiting for their next meal. Some people have even trained them, one person trained their green spotted poffer to put a ball in a hoop.
[This message has been edited by jmbishop (edited 09-24-2014).]