Though the exact nature of his powers vary between stories, Maui is so strong that he's able to create entire islands by himself. Once when he was on a fishing trip, his fishhook latched onto the ground by accident and he eventually pulled up several large “fish” that would become the islands of Hawai’i.
Maui is a figure who appears across many different Polynesian cultures, including Hawai’ian, Maori, Samoan, and Tahitian. As such, his story tends to change depending on who’s telling it — in Maori mythology, for instance, he follows his brothers on a fishing trip and pulls up the New Zealand islands with his fishhook.
The Disney version of Maui was abandoned by his family as a baby and saved by the gods. This lines up with the Maori version of his backstory, but it leaves out details such as how he was formed by the waves after his premature birth, found by his grandfather, and eventually sent to find his original family.
Maui usually has siblings who aren't in “Moana,” including several brothers and sometimes a sister (according to Maori tradition). But no matter the variables, Maui's relationship with them always seems to be strained — he's constantly looking for ways to get back at them whenever he feels slighted.
There is more to the story of Maui lassoing the sun than a lyric line in “You’re Welcome.” The Hawai’ian version says that Maui forced the sun to slow down because his mother was sad about not having enough daylight to dry her clothes, while the Maori version has Maui physically striking the sun.