Guild Wars 2

I was just fighting a necromancer one on one in WvW combat with my warrior, and I was beating him easily, until he summoned 3 arctodus that just mauled me. Can anyone tell me how he did this? They were not creatures that were already there that just jumped on me. Somehow he made them appear and they attacked and killed me. I can’t find this as an ability anywhere.

could be something SIMILAR to this http://wiki.guildwars2.com/wiki/Ogre_pet_whistle . Doesn’t list Arctodus, but perhaps there exists something similar.

Isn’t there a rune that does this with the 6th rune equipped?

Edit: nvm that’s a drakehound. Maybe they were just neutral mobs that aggro’d on you?