After more testing, the pufferfish now only deals damage to hostile creatures and players, even if non aquatic creatures or axolotls approach it and cause it to swell, or if it is causing damage to hostile creatures, these non hostile creatures will not be harmed.
After more testing, the pufferfish now only deals damage to hostile creatures and players, even if non aquatic creatures or axolotls approach it and cause it to swell, or if it is causing damage to hostile creatures, these non hostile creatures will not be harmed.