Shelob's babies of Mirkwood (DISCUSS THE SCARY SCENE)

It was quick and easy because Jackson just had to give us the Tauriel-Kili romance rather than adapting things actually in the book.

Requiescat in pace, Krystle Papile. I'll always miss you.

They are actually Shelob's offspring. Tolkien explains this when he introduces Shelob in The Two Towers:

"There agelong she had dwelt, an evil thing in spider-form, even such as once of old had lived in the Land of the Elves in the West that is now under the Sea, such as Beren fought in the Mountains of Terror in Doriath, and so came to Lu´thien upon the green sward amid the hemlocks in the moonlight long ago. How Shelob came there, flying from ruin, no tale tells, for out of the Dark Years few tales have come. But still she was there, who was there before Sauron, and before the first stone of Barad-duˆr; and she served none but herself, drinking the blood of Elves and Men, bloated and grown fat with endless brooding on her feasts, weaving webs of shadow; for all living things were her food, and her vomit darkness. Far and wide her lesser broods, bastards of the miserable mates, her own offspring, that she slew, spread from glen to glen, from the Ephel Du´ath to the eastern hills, to Dol Guldur and the fastnesses of Mirkwood. But none
could rival her, Shelob the Great, last child of Ungoliant to trouble the unhappy world."