Be careful with valentini puffers. Mine started off sweet, thought I had a "good" one. Then it got the taste for blastos. Its beak made short work of them. Took me 3 days to realize it was him. Also couldnt keep hermits or snails, devoured them as soon as they hit the sandbed. Also SPS tips was a favorite nibbling snack. I finally got him out, I couldnt be happier.
*edit Forgot to add something important. His "bad" behavior began 4 months after I got him. My theory is he stole mysis from a blasto and got a bit of blasto by mistake and said to himself thats delicious!