FormerlyHemlock
Hero
I seem to recall the Tarrasque having regeneration in previous editions. Wonder why they took it out....would address this very annoying situation, which may technically be accurate, but really really dumb if it ever happened.
Yeah, unstoppable regeneration was the AD&D's Tarrasque's defining feature. I don't know what happened between AD&D and 5E or what the Tarrasque was like in between, but when I saw the 5E Tarrasque had no regeneration at all I was... aghast.
Fortunately it's easy to add back in. It's not quite sufficient on its own to make the Tarrasque a real civilization-ending terror (you can still petrify or drown it or True Polymorph and then Magic Jar it) instead of an uber-troll, but it prevents the Tarrasque from being trivially solved via attrition and mobility. In AD&D you needed to be at least 7th level to have a real chance at beating the Tarrasque and adding 20 HP per round of unstoppable-without-MacGuffin regen, plus a burrowing speed and also removing the range limitation and immunity-once-saved clauses from the Tarrasque's fear, puts the Tarrasque back at approximately the "right" level of difficulty to be fun, IMO.