Pokémon X and Y Walkthrough, Pokémon Move Sets: Tyrantrum
(Please note that the recommendations below are largely made for in-game play. A Tyrantrum in a competitive environment will likely make use of different moves to accommodate for smarter, more adaptive opponents. If you have any move set suggestions, feel free to toss them into the comments.)
Dragon-type pokémon seem to hold the universal advantage of being among the coolest-looking pokémon around, and the sixth generation continues this trend with Tyrantrum. Big, mean and all-powerful, Tyrantrum plays out pretty much exactly as you'd expect.
Type: Rock / Dragon
Tyrantrum evolves from Tyrunt at level 39.
Electric, Fire, Flying, Normal, Poison
Dragon, Fairy, Fighting, Ground, Ice, Steel
What a bruiser. Tyrantrum is heavily weighted in Attack and Defense, like many rock-types, and is quite capable of both withstanding and dishing out some rather mean attacks. (That's good, too, given its largeish list of vulnerabilities.) Its Special Attack is negligible, its Special Defense is even worse, and its Speed... eh. So so. It's not as slow as it looks, but Tyrantrum is still pretty slow.
The big problem here is Special Defense. Tyrantrum isn't aces when it comes to HP, though it can still resist most physical attacks. Special attacks, though? Tyrantrum falls. Hard. You'll have to deploy your t-rex buddy carefully to get around this shortcoming.
Strong Jaw: Biting moves are boosted in strength by half. This should enormously useful, as Tyrantrum basically gets STAB-level bonuses with the right moves, but... well, only Bite and Crunch fall into that category. Not as great as it should be, though Strong Jaw effectively turns Tyrantrum into a dark-type without adding any additionally weaknesses.
Rock Head: Removes the damage done when using moves that cause recoil. Helpful, but given the nature of Strong Jaw, not as useful as it is on some other pokémon. This is a Hidden Ability.
It's a slow sweeper, but Tyrantrum is a sweeper nevertheless. It has enough raw attack power to chew through pokémon whether they're ably protected by typing or high Defense scores. Gift the thing with Dragon Claw and Head Smash / Stone Edge to take advantage of STAB, then laden it down with any other hard-hitting attack moves not already represented in your pokémon team. Earthquake is a great choice - and is naturally learned! - as well as Brick Break and Return. Giga Impact's an option, as Tyrantrum also learns it, though Return will suffice for the majority of encounters. If you want to speed things up, toss in Rock Polish as well.
Tyrantrum can also make a fairly good tank, so long as you're facing physically-inclined opponents. Give it at least one STAB move, then teach it Stealth Rock and possibly Sandstorm to slowly wear down opponents. Toxic is always an option, though you're better off taking advantage of Tyrantrum's unholy Attack stat with something that does STAB.
EV / Super Training
Since it's already terribly powerful, Tyrantrum could really use a boost in Special Defense. It's great at OHKOing opponents, but only if it survives to the end of the round. Barring that, you can focus on its HP, which is almost never a bad idea, or try to make your Tyrantrum fast with a boost to Speed. So long as you can outrun or outlast the inevitable Surf or Ice Beam, your Tyrantrum can do the rest.
Catching a Tyrantrum
You don't 'catch' a Tyrantrum in Pokémon X and Y, per se. Instead, you'll have to resurrect one. On your first visit to Glittering Cave you'll get the pick of a fossil at the end; choose the Jaw Fossil. Bring it back to life in the Fossil Lab of Ambrette Town to receive a Tyrunt, then level up to 39 to get your Tyrantrum.