Toypocalypse is necessary if you want to earn Winter’s Presence, and sometimes shows up for the daily. This GW2 guide shows you the best way to play (and win!) Toypocalypse with minimum effort.
The official Guild Wars 2 wiki has an extensive Toypocalypse strategy guide available, if you really want to get into this event. But there’s no need to make things that complicated.
Pick up Snow and Scraps, and use them to build snowmen, ballistas, and catapults. It’s better to build more individual units, rather than upgrading existing units. Build these in a circle around the edge of the central pavilion. It’s also useful to build groups of siege in the general area where enemies spawn, and inside the grid of walls directly north of the central pavilion.
Just keep building siege. Don’t bother attacking enemies unless they manage to enter the central pavilion. Enemies hit hard: if you need to heal, go to the dolyaks. If the dolyaks need to heal, feed them hay.
As soon as Toxx appears, call out a target on her (Ctrl + T). Attack Toxx, and use any knockbacks to drive her away from the dolyaks in the center.
Keep building siege until the match is over.