One of the cosmic race known as the Celestials published by Marvel Comics. Oneg the Prober first appeared in Eternals #9 in 1977 and created by Jack Kirby.

The Celestials travel about the universe, inspecting worlds and their inhabitants for their fitness. Each of the Celestials have a specific task to fulfill with their names reflecting the task they perform. Arishem the Judge is the final authority of the fitness of a world. Exitar the Executioner carries out the destruction of worlds or races should they be judged unfit to continue.

Then, there is Oneg the Prober. Oneg is one of the few Celestials that seem to perform multiple tasks. The first is relatively straight forward. When the Celestials go to a world, Oneg the Prober explores and inspects the world itself. He delves into the planet to discover its make up and origin as well as inspecting the various continents. He has been seen in comics inspecting the continent of Australia on Earth.

The other task that Oneg performs is linked to the Celestials occasional decision to introduce additional genetic material into a race's DNA. This insertion of genetic material to an entire race is the job of Oneg the Prober.

The exact procedure by which the insertion is performed has not been recorded to date, but one has to imagine that it involves all of humanity being invited out for drinks by Oneg after being introduced by Exitar at a party. Oneg and humanity then go out for dinner and dancing, during which humanity and Oneg exchange a few smoldering looks. Oneg invites humanity back to his spaceship after humanity gets all slutty, and after Oneg uses the world "soul-mate" a few times and swears that the Skrull never meant anything to him, they spend a whirlwind hour together while Oneg introduces the genetic material into humanity. Humanity then has a cigarette, which sometimes causes an ice age, having that much smoke introduced into the atmosphere at once. Then there are some vague promises from Oneg about calling and humanity takes a cab home. Humanity hears a week later that Oneg has left the planet and was seen leaving a club with those skanky Kree.

Oneg the Prober appears as the rest of the Celestials do, as a two thousand foot tall armored figure. He possesses cosmic powers that include energy manipulation, near invulnerability, and the ability to travel unaided in the space.