SMG4: Treasure Hunt With The Bois is the thirtieth episode of Season 9 and the five hundred and eighteenth overall to be uploaded by SMG4.
This episode was aired on August 10, 2019.
Mario and the bois come across a treasure map to the lost city of gold...
Mario goes fishing with Bob for a Cheep Cheep, but Fishy Boopkins prevents them, as the Cheep Cheeps happen to be his friends. They also fish Shrek, who demands to know what they are doing in his swamp.
Meanwhile, Axol's Inkweaver is stolen by Teletubbies. Just then, Mario and his friends arrive where they help Axol repel the Teletubbies by having Mario fish out Shrek and letting him deal with the rest of the Teletubbies. Fortunately, he happens to know where they are headed, which is the Lost City of Gold and allowed Mario and his friends to join him as a thank you for saving him. He also happens to possess a map of the location.
The four of them encounter Dr. Robotnik leeches. Fortunately, Mario knows that they can repel them using fire. However, he can no longer feel his face.
Mario, Fishy Boopkins, Bob, and Axol then attempt to use Donkey Kong to help them get to the city of gold, but he ends up making them fall off a cliff.
Bob attacks Yoda, only to incur the wrath of two more muscular Yodas. The four of them end up falling from a great height, but Axol prevents their deaths by using two spare pens and slamming them onto the stone wall to reduce their speed.
Fishy Boopkins predicts that the Lost City of Gold is behind a waterfall, but there doesn't seem to be anything there. However, upon closer inspection, they have found the city of gold.
The episode then ends with a cliff-hanger but then, Luke Lerdwichagul and Kevin Lerdwichagul popped up to remind the viewers that it will not be an arc but rather, a mini-series/mini-arc. They will also let them know if an arc is upcoming by saying so directly to the viewer.