Turtonator will probably be back.
We have met quite a few of the new Pokemon making their way to Pokemon Sun and Moon, including "Alolan variants" of classic monsters like Exeggutor, Vulpix, Ninetales, Sandshrew, Sandslash, Meowth, and Marowak.
In a new trailer yesterday, fans were introduced to a new creature - Turtonator. Turtonator, the Blast Turtle Pokemon, is a Fire/Dragon. As the awesome name suggests, Turtonator is a turtle-looking creature that can make things blow up. Its shell is covered in a layer of explosive material. According to the accompanying press release, whenever anything strikes Turtonator, sparks fly from the horns on its shell (horns on its shell!), igniting the explosive layer and causing an explosion.
The press release further detailed the new badass. Check it out:
"Turtonator can learn the exclusive move Shell Trap. With this move, the Pokemon lays a trap for the opponent at the start of the turn. If Turtonator is hit by an opponent's physical attack during that turn, the trap triggers an explosion resulting in huge damage to the opponent."