Guild Wars 2 MMORPG gameThe Guild Wars 2 official site is enriched with the Ranger class description, along with the pets that will join him.

The ranger is a jack-of-all-trades and a master of them all as well, relying on his keen eye, steady hand, or the power of nature itself. A master of ranged combat, the ranger is capable of striking unwitting foes from a distance with his bow. With a stable of pets at his command, a ranger can adapt to his opponents' strengths and weaknesses.

A ranger is accompanied by his pet, a loyal animal companion. Rangers charm pets and then bond with them. A ranger can have up to three pets at his call, but generally speaking, only one pet can be active at any time. Pets' base health, armor, and damage are based on the level of the player that owns them.

You can read more about the Ranger here.