The Bermuda Triangle is a mysterious portal that first appeared in Moai Better Blues, later again in Chariots of The Dogs and shortly at the start and the very end of What's New, Beelzebub?
In Moai Better Blues[]
The triangle is first seen chasing Sybil until Sam throws a red colored, octagonal-shaped object, the portal's weakness, into it, causing it to suddenly stop. As Sybil calms down, Lincoln is then sucked into the portal. Panicked, she jumps in as an attempt to save him, followed by Sam & Max out of curiosity. All four of them are transported to Easter island, where the events of the episode take place.
The Freelance police later learn that the portal was sent by none other than Mr. Spatula. suddenly driven by 'pure evil.'. This subject is later brought up again in episode 5, where they learn that the Soda Poppers forced him to in order to banish the duo.
In Chariots of The Dogs[]
When the duo, joined by Bosco, finally confront T.H.E.M, it is revealed that they had captured the triangle as a method of transporting souls into hell, as shown with Jurgen and Bosco's. The episode ends with Sam & Max once again entering the portal to retrieve Bosco.
In What's New, Beelzebub?[]
The triangle ends up transporting the duo to the sewers so that they can reach Hell and rescue Bosco.
The Bermuda Triangle appears in the very final scene of Season 2 as it pours lava directly from the volcano back at Easter Island onto the Soda Poppers, killing them.