Origin

In an effort to understand and recreate the accident that created the Hulk, Bruce Banner began experimenting by irradiating various animals with gamma radiation. Amongst those animals he experimented on was 27 and his brother 26, a pair of boars so named because they were the 26th and 27th experiments. 27 was granted advanced intelligence and strength by this exposure to radiation. He and his brother became devoted to serving Banner. 

Creation

27 was created by Jason Aaron and Marc Silvestri. 

Major Story Arcs

Hulk Asunder 

27 and his brother are sent by their "father" to scour the island for possible test subjects. Failing in this they are sent after the Hulk, who has retreated to the Moloid caves. 27 and his brother attack the Moloids, kidnapping the children of the tribe. This draws Hulk to them, and the brothers engage in a fierce battle with the Hulk, who beats them severely. The fight is abruptly ended when 26 plunges through a hole in the Earth's crust that the Hulk had created in the midst of the fight. 27 pauses to mock the Hulk before allowing himself to fall through the hole to be with his brother. He survives the fall, but has been severely wounded by the fight and the fall. His fate is unknown, but he is presumed dead. 

Powers and Abilities

Due to his irradiation, 27 is larger than an average boar, and capable of walking bipedally, as well as speaking and understanding English. Both his strength and his durability are greatly enhanced, and he also possesses enhanced intelligence, though his intelligence is not greatly enhanced when compared to a human.