Goblins have long been one of the most powerful tribal creature types in the game. Even in Eternal formats, goblin-based decks can be extremely fast and remain competitive. They are primarily small, cheap creatures, and as is common for goblins in most fantasy settings, work best when you have many of them in play. Because they are small and cheap, many goblin cards actually expect to die. (create) is actually worth more dead than alive, and Mogg Fanatic is ready to dive-bomb itself at any given moment.
Due to the competitive status of goblins in red, Lorwyn Block put them primarily in black with red as their secondary color. This exposure to black allowed goblins to gain a reanimation aspect (represented by a tremendously high birthrate), and thus reduce the potential drawback of their kamikaze tendencies.
Small, mischievous, dimwitted goblins that live in the Sokenzan mountain range of Kamigawa. They are long-armed, shelled creatures who take glee in pulling tricks on travelers. Unfortunately, these tricks generally involve the launching of fireworks, avalanches, fire traps, or just general savage beatings.
Native to Lorwyn. Unlike most Goblins, Boggarts are primarily black-aligned, as opposed to red. They form large, self-contained clans that live in swamp warrens under the leadership of an Auntie. Boggarts occupy themselves by playing tricks on the other races in order to acquire "treasure" - anything from a bucket to rare jewelry. Boggarts then share the loot - and, more importantly, the story - with the rest of their clan. Anyone who refuses to do so is exiled.
The Kyren goblins live on the plane of Mercadia. They are much smarter than Dominarian goblins, but also cowardly. They always speak in questions and never allow wrong answers. When the Weatherlight planeshifted to Mercadia from Rath, the Kyren made cabin hand Squee a general. However, Squee soon discovered that the Kyren were building flying ships for the Phyrexian invasion of Dominaria. Surprisingly, the Kyren originated on Dominaria. When Yawgmoth began his conquest of the city states of Halcyon, a planeswalker named Dyfed and the wife of Yawgmoth's enemy, Rebbec, transported the nobles to the plane of Mercadia. With them they brought Glacian's (Rebbec's husband) goblins. This was done for protection and to forage for food. Over time they realized the nobles needed them to live, and started manipulating them so the goblins came in control, and eventually evolved. Their most favored weapon is the blow dart.
A vicious, strong and particularly stupid breed of Goblin native to the artificial plane of Rath. Moggs were trained to find artifacts by smell by Volrath, evincar of Rath, whom they served blindly.