Cleon
Legend
That all sounds reasonable.
Good!
Armour Class: 14 (+1 size, +3 natural), touch 11, flat-footed 14
Swim 30 ft.? Maybe have it act as heavily encumbered when "puffed up", so it slows to 20 feet.
It's got a nasty venom - looks like Con damage, probably with a racial bonus or Ability Focus to boost the DC.
Do we want it to be potentially fatal like the original or cut it down to nasty but not likely lethal? Maybe 1d6 Con?
3-12 damage for the spines seems an awful lot considering its size and strength. Shall we trim the spine damage down?