Raga is a sentient planet. Raga and his siblings yearned to have life on their surface and they each searched out inhabitants. But soon they learned that smaller life only took and killed themselves, destroying and scaring. Raga fought back by killing all his inhabitants, and these action cause one of his brothers to kill him.
Raga was created by writer Justin Jordan and artist Diogenes Neves and first appeared in Green Lantern: New Guardians #31.
Major Story Arcs
For more information see: Green Lantern: New Guardians #31
Kyle Rayner finds himself on a dead world, and wanders toward a city in the distance. There he finds signs that life used to be plentiful on the now dead planet. He soon realizes he is being followed by some sort of life, and comes to the conclusion he is on a dead version of Mogo. He then flies to the "Heart of a Living Planet" and uses his White Power Ring to give the heart a spark of life.
This makes Raga less dead, and he communicates with Kyle, he tells of how he and his sibling yearns to witness life and this was his siblings down fall, but not Raga nor his brother Mogo. Raga kills all life on his surface and causes Mogo to kill Raga.
But now Kyle gave him his spark of life again and now Raga is going to spread across the universe and kill all life. Upon learning this Kyle destroys the spark of life making Raga completely dead once again.