16. "Night Of The Dolphin" (Treehouse Of Horror XI, 2000)
This story often gets overlooked because it was included in an otherwise dreadful Treehouse Of Horror episode, but it's actually one of the better segments to ever be produced. While the other tale in this eleventh Treehouse installment features a mind-numbing story that has the Simpson family transformed into Grimm’s Fairy Tales characters, "Night Of The Dolphin" thankfully gets back to the horror roots of these episodes, complete with pervasive gore and a heaping helping of death.
After Lisa frees a show dolphin, named Snorky, from an amusement park called Marine World, it gathers up hundreds of other dolphins in order to take revenge on Springfield. The segment soon devolves into a hilarious battle between humans and the dolphins in the streets of downtown Springfield. If seeing Groundskeeper Willie get impaled by the snout of a bottlenose dolphin doesn't excite you, then you need to get your pulse checked.