The Presidentress of The Mega Gargantuans is the political leader of the entire Mega Gargantuan species, a molecular species that resides in a city in the Amazon Rainforest. She appeared in "The Rickchurian Mortydate".
In "The Rickchurian Mortydate", scientists discovered the Mega Gargantuans in the Amazon Rainforest. Rick and Morty went to explore the Mega Gargantuan Republic, but The President had the same plans. Due to Rick and Morty's recent betrayal of him, The President didn't allow them to go on their adventure there and instead, investigated the scene himself, shrinking down with Shrinking Pills (which made him shrink out of his clothes in the process).
When being met by The President, The Presidentress informed him that Rick and Morty had already met with her before he could even get there. (Achievable with their instant shrink ray and teleportation technology) The two of them lied to her, saying they were his ambassadors. They convinced her that The President liked showing his dick off and swinging it around, and gave her a shirt for The President to wear, but didn't include any pants.
- "Presidentress" is actually a confirmed word in the English language, and as one might assume, it means "female president". However, since there have never been any American female presidents, throughout the history of the word's existence, the word was very rarely used, and basically forgotten. Nowadays, the word can be considered archaic, not even being used, when one talks about a hypothetical female presidential monarch, whereas they instead use the term "female president".