can it "fit" into one? Yes.
should it be on one? No.
15 gallons is generally the minimum for a single figure 8 puffer. 20-29 gallons is preferred.
Are you planning on making it brackish?
Please go for a 20 long or 29 gallon. If you get a 29 you could probably put some bumblebee gobies in there tooYes i would. I dont have a tank yet but noticed petco's sale and wanted one
If you absolutely must go the 10g route pick up a few dwarf puffers instead. Very fun little fish.