Fanaelialae
Legend
My father had a golden retriever that was very smart, and part of the family, one day my step sister came home to find it very hurt and bleeding, she pulled through but boy was my dad pissed. a couple of jerk kids about early teens stood 15 feet from her (she was on a 10 foot chain) and pelted her with rocks after school...
now that dog would kill for my dad, and was the smartest dog I ever meet. She never thought to throw a rock back... I currently have a rather normal intelligence mini schnauzer... he is a snaper and a loud barker... but a leash stops him, and as such I assume all dogs.
The big T is about on par with a smart dog... what makes you think it is anymore likely to develop an new unique strategy?
to both of you... This is not some "well the orc can do what the PC can do" situation... it is the INt 3 Tarrasque... so stop asking stupid "Can you pee?" quastions look at this case, a CR30 ANIMAL intellect with no defense against ranged attacks, and by the rules no way to reatch some targets
It's not perfectly clear that the Tarrasque has an animal intellect. While the MM Mastiff does have an Int 3, so might a Half-Orc Fighter, and I don't think most DMs would question the latter's ability to throw objects.
Besides, even if we assume that the Tarrasque's intellect is equivalent to that of a smart animal (as opposed to a very dumb human), the Tarrasque is potentially eons old. In that time it may have picked up a few tricks that a dog (with a lifespan of one or two decades) wouldn't. Elephants, for example, are long lived animals that are known to throw objects.