Elfzilla is an army list template used for Eldar. It was used in 4th and 5th edition WH40K as long as Phil Kelly's 4th edition Eldar codex was recent.
The list takes its name from the more popular Nidzilla list. It, too, uses as many monstrous creatures as possible. Sadly, for Eldar, this means only 4, not 8, as with Tyranids.
The basic setup is
Since Wraithlords have the wraith sight disability, several spirit seers are also needed. Because both the Wraithlords and their guide dogs are prone to being shot dead (krak rockets fit quite well with AP3 and S8), they need some walking cover. Monstrous creatures need a lot of physical cover to get a cover save. Luckily, Wraithguard are quite tall and can provide cover, plus they are able to take a beating.
A typical choice therefore is 10 Wraithguard and an attached spirit seer, used as a troop choice.