The River Twygz is a subsection of The Underwhere in Super Paper Mario. It is evidently filled with the tears of sinners that give it a purple color. Charold will ferry the player across the river for 4 coins, but it is not required. The river is inhabited by Underhands, invincible, skeletal hands that will damage Mario and co.
When Mario is asked by Queen Jaydes to search for Luvbi, she mentions to him that someone dressed in green clothing was seen falling into the river; while remarking that this could not be the missing Nimbi, she advises that the hero investigate the sighting, granting him a key so that he can explore the riverbed and the tunnels beneath it. This man in green is Luigi, who presumably fell into the River Twygz after being sent to the Underwhere by Dimentio. After solving a series of puzzles, Mario is reunited with his brother, and the two continue the search for Luvbi.
The name of the river is a pun on the River Styx (commonly pronounced "sticks", whereas this river is pronounced "twigs"), a similar river in the Greek Underworld. In Greek mythology, souls of the dead are ferried across the river by Charon (himself represented by Charold), and if one were to fall in, they would be granted immortality, but be pulled under by the hands of souls trying to escape the river. The Underhands are likewise based on the souls in the River Styx, which may also be referenced by the unintelligible voices that can be heard in the music that plays at the river's bed.
Names in other languages