Manipulative Monstrosities is a blue/red intro pack centering around the Monstrosity mechanic.

With the "Manipulative Monstrosities" deck, you can command colossal Krakens, gargantuan Giants, and the forces of nature itself to smash your opponent into submission.

This deck aims to control the early game with defensive spells until it can crush the opponent with powerful monsters. Red direct-damage spells like Shock and Lightning Strike will zap early creatures, while tricky blue spells like Griptide and Dissolve will throw off your opponent's plans. Many of your spells feature the scry mechanic, which will help you find your creatures or the lands to cast them.
Later in the game, your Giants and sea monsters will dominate the battlefield with the monstrosity ability. Once your creatures become monstrous, they'll be positively enormous, often with a one-time additional bonus. Stoneshock Giant sets up a big attack, and the mighty Shipbreaker Kraken grabs up to four of your opponent's best creatures in its tentacles. If you have two or more big creatures in your hand, it's a good idea to cast them all before you start activating their monstrous abilities. That way your strategy won't rely on just a single creature, in case your opponent has a kill spell or a trick.

Krakens and sea monsters aren't the only wonders you'll uncover in the Theros set. You'll also find potent spells like Steam Augury and Anger of the Gods, which will help you control the game. You may even encounter the elusive Prognostic Sphinx, a powerful flier that lets you scry whenever it attacks. And if you devote yourself to Thassa, God of the Sea, she can aid your cause herself by guiding your fate and drowning your enemies.