Power Team Vanquish is a Weekly Event game mode in Plants vs. Zombies: Battle for Neighborville. It is a variant of Team Vanquish where a crystal dog will spawn in a predetermined spot on the map, which grants its users a temporary invincibility and boosted damage.
What's in a Crystal Dog anyway? Well, only UNLIMITED POWER! (Disclaimer: Unlimited power only lasts a limited time, some exceptions may apply).
Because this mode includes a crystal dog that gives the player that obtains it a boosted damage and temporary invincibility, which spawns at the same spots on each map, it is recommended that you camp near these places so you or your team can pick it up and kill enemies with it seamlessly. This also helps making the weekly challenges that involve killing enemies while invincible easier.