I've had this Valentini Puffer for at least several months now (not exactly sure, time just disappears) and this is the second time I've observed it acting like this. Not to mention it allowing the Gramma to "bite" it (seems more like a "get out of here" to me, as the puffer is digging up the lawn right outside where the gramma lives [this is the only time I've seen "aggresion" from the gramma towards the puffer]).
Wondering if there is a reason for this behavior? A couple of minutes before this the puffer puffed up (only the second time I've seen it) and quickly swam to the back of the tank and started digging. This is the second time I've seen it puff up ever, with the same behavior. What's more interesting to me is that the puffer seemingly is entirely unconcerned that the gramma is biting it (3:30, 5:30 timestamps).
After this whole ordeal of about 15-30 minutes, the puffer seemed to be teasing the gramma by following it around for a bit as if to egg it on.
I feed my fish Saki-Hikari pellets daily, then in the evening alternate between Hikari Brine and Mysis or Reef Rod's Fish Only or Reef blend whichever I feel like preparing at the time. Puffer gets some Hikari dried krill handfed for it's teeth. I saw some posts on various forums about puffers getting "tummy-aches" from overfeeding, but not enough reading to corroborate it.
Did introduce a new fairy wrasse today, but that doesn't align with the previous similar behavior. The puffer doesn't care about anyone else, except my citron clown goby will randomly charge the puffer.