The Beastlord class is a unique class that is a hybrid of the Shaman and Monk parent classes. One of the class's distinguishing features is the ability to summon a warder pet to fight alongside them. The form the warder takes depends on the race of the beastlord.
First pet becomes available at level 8, and is based on the race chosen at creation:
Barbarians - Wolf
Iksar - Scaled Wolf
Ogre - Bear
Troll - Lizard
Vah Shir - Tiger
Wood Elf - Treant
Beastlords are moderate DPS (generally comparable to monks, but less than that of rogues or berserkers) that fight with their warder (at least in a group setting) with relatively useful utility abilities and toned down versions of shaman buffs. Beastlords have a unique line of mana regeneration abilities starting with Paragon of Spirit and greatly improved in SoF by the addition of a single target version on a two minute refresh timer, have the unique Spiritual Enlightenment line of mana/hp regeneration buffs, and also have unique attack buffs, the Ferocity line. Beastlords can also slow.
Depending on equipment choices and a person's playstyle, beastlords can however fill different rolls. Beastlords may focus on things that make them better able to heal, allowing them to better heal their pet and even help out healing a group, or maximize their damage output, or even focus their gear choices in a way that lets them tank in many or most XP groups.