The Maker

A person/people (often a god, although the occasional Mad Scientist or Evilutionary Biologist dabbles in this as well), that has/have created an entire place or species. Frequently in fantasy fiction, there are often several creators of the races that inhabit the world, and the ones who created them often labeled as the King of the Gods of the race's respective pantheon. The creator of the world or setting is often above these gods, someone who may in fact be the God of the Gods.

A common subtype has a being that personally created the monsters of the setting, which is usually inspired by Echidna, who mothered most of the monsters found throughout Greek Mythology.

A Creation Myth often involves a character of this type, although what's made could have been created without the involvement of any being whatsoever. Some type of spontaneous generation, perhaps?

Examples of The Maker include:

Anime and Manga

The Lifemaker in Mahou Sensei Negima.
In Umineko no Naku Koro ni, Maria is thought to be able to become a Creator witch - a witch who is able to create a world out of nothing.

Comic Books

Franklin Richards, of Marvel's Fantastic Four, who once created a pocket universe in order to reincarnate his family and the Avengers after they "died" fighting Onslaught.
Superman, who creates an entire pocket universe in All-Star Superman.
In the Mega Crisis Crossover DC vs Marvel each of the two universes was created by one of two superdeities called The Brothers. Presumably they have a father & mother, as well as some other siblings to oversee Dark Horse Comics, Image Comics, etc.

Literature

Eru Iluvatar from The Silmarillion, The Hobbit, and The Lord of the Rings.
Aslan from The Chronicles of Narnia.
Discworld has three: The Creator who began the entire universe (with an analog to a musical number), the being who built the actual Disc (on commission), and the God of Evolution who designed most of the actual species (carefully ignoring the fact that by the definition of evolution, his job makes no sense). Incidentally, Rincewind has, at least indirectly, interfered with all of these.
Starmaker, by Olaf Stapledon, is a 1937 science fiction novel which broke new ground by exploring the concept in relationship to the size and scale of the known universe and the fact that most of the universe seems to consist of empty space with occasional blobs of flaming hydrogen.

Mythology and Religion

God.
Tiamat (not to be confused with the five-headed dragon from Dungeons & Dragons).
In Greek Mythology, the Titan Prometheus crafted the first humans out of clay.

New Media

Kennet Shardik of The Journal Entries basically creates an entire world and more than ten different races to populate it.

Tabletop Games

Dungeons & Dragons has many stories of the origins of civilized races, except humans, ironically, their lack of a racial "hat" makes their myths far too varied:
- Moradin created the first dwarves out of earthen materials using his divine forge, and then tutored them in the skills they became famous for - blacksmithing, metalworking, gemcutting, and the like.
- Elves and Orcs share a creation myth - which varies widely depending on who tells it - but most agree that they were born from the blood of Colleran and Gruumsh during an epic battle between them at the Dawn of Time.
- Gnome myths claim their chief god, Garl Glittergold discovered a cavern full of the most beautiful of gemstones; he breathed upon them, his divine power turning them into the first gnomes. He also told these first gnomes some funny stories, giving the forebearers of the race their well-known sense of humor.
- Halfling lore claims their people always existed, but were uncivilized and primitive until the goddess Yondalla found one of them named Littleman (a heroic halfling who actually features in more myths than Yondalla herself) and offered to teach his people the ways of civilization in exchange for their reverence. Yondalla is thus viewed as an adoptive mother of the halfling race.

Video Games

Arceus from Pokémon. According to the Pokedex in Pokémon Black and White "It is said to have emerged from an egg in a place where there was nothing, then shaped the world."
The Maker from Dragon Age. Or so the Chantry claims: In-Universe theories are abound that "the Maker" is simply a particularly powerful Fade spirit whose authority nobody dared to challenge.
You, the player, in Spore.
In the Myst universe, the race of D'ni believe in a god called "the Maker", who it is believed wrote everything into existence (as Rewriting Reality is a major theme).
Jubileus from Bayonetta is explicitly called the Creator by several accounts, including various enemies in the game. In The Hierarchy of Laguna, she is the only Angel with the title of Dea (Goddess in Latin). She also is a major example of Light Is Not Good, as Jubileus is the Sealed Evil in a Can Final Boss.
The creator god in Final Fantasy XIII is identified as the Maker. It turns out that the entire conflict between Pulse and Cocoon has been engineered by the fal'Cie in an attempt to summon him back to fix their mistakes.
Luther Lansfeld in Star Ocean: Till the End of Time is revealed to be the creator of the Universe. In this case, he is actually a programmer who created a virtual universe inside a simulator.
The various worlds in Might and Magic were created by The Ancients, an enigmatic race of Sufficiently Advanced Aliens as part of a widespread Magic Genetics project, each world being a biosphere, or part of one. To varying degrees of success.

Western Animation

In a Halloween Episode of The Simpsons, Lisa inadvertently creates a species of tiny people in a petrie dish, who look on her as their God (and Bart as the Devil).
Franz Hopper in Code Lyoko, who built and programmed the eponymous virtual world, inadvertently creating XANA as well.
Primus, the creator of Cybertronians in Transformers. Also a Physical God, and sort of a Genius Loci, since he's Cybertron itself.