Mother Gothel was the primary main antagonist of Disney's 2010 animated feature film, Tangled.
History
Tangled: Before Ever After
Gothel makes a cameo appearance in one of Rapunzel's paintings during the prologue
Gothel is also alluded a few times; when King Frederic and Queen Arianna discuss why he's so overprotective with Rapunzel, he mentally flashes back to the night Gothel broke into the castle and kidnapped Rapunzel.
During the climax, the antagonistic Lady Caine warns Rapunzel that, "she has no idea who's she's dealing with", to which Rapunzel retorts, "Believe me, I've dealt with much worse."
Tangled: The Series
In the episode What the Hair?!, Gothel appears in a nightmare had by Rapunzel. After sadistically bragging about her supposed return, Gothel summons the thorn-like rocks that appeared on the night Rapunzel's hair mysteriously returned.
Gothel takes notice of the hair and suggests that she and Rapunzel return to the tower where the latter will be "safe". Rapunzel abruptly wakes from the nightmare, though it prompts her to learn more about her revived hair.
During the latter half of the first season (specifically in The Alchemist Returns and Secret of the Sun Drop) King Frederic had been accused of mistreating Rapunzel in a manner eerily similar to Gothel, as he had been caught lying to Rapunzel and demeaning her by limiting her freedom. Rapunzel would eventually come to discover the difference between the two, however, as Frederic's actions were out of love, whereas Gothel's were out of selfishness.