These gods and heroes didn't rely on Mom and Dad to get where they are in life. No, they did it themselves. Atum sprang from the waters to create the world, while his buddies Cecrops, Olorun, and Tiamat also made their marks in the world on their own. Talk about independent.
Cecrops, first king of Attica, didn't start out as your average baby boy. He was an autochthon, which means he was "born of the earth" (he popped out of Mother Gaia fully-formed) and was half-dragon. During his reign, he saw Athena become patroness of Athens; ever the careful king, Cecrops made sure to keep Poseidon happy, too.
A West African god, Olorun was the head honcho of his Yoruba pantheon. Thanks to Olorun giving permission, the gods created good, old land for humans—and deities—to stand on. After a weaving contest, Olorun became supreme god of the Yoruba, even over his female counterpart, Olokun.
Tiamat is kinda similar to Atum's Nu, in that both are the primordial waters from which everything emerged. Tiamat, though, isn't that pretty—she's a big ol' dragon. Like Atum, she gave birth to the first gods, but unlike Big A, she had to have a partner to do it. He brags about his self-sufficiency a lot to her.