At the very start of Crucible of Eternity explorable mode, there is a hallway containing of 6 silver mobs: 2-3 icebrood elementals, 0-1 icebrood goliath, 0-1 icebrood colossus, and 2-3 icebrood wolves.
I noticed a strange bug with the icebrood wolves playing as a mesmer. These silver wolves spawn additional normal wolves. If you allow the wolves to reset, the spawned normal wolves do not despawn and it becomes impossible to attack them with clones or phantasms. You can spawn the clones/phantasms on them but the illusions will just stand there and not attack. If you try to shatter with f1-f3, the illusions will still not move and the shatter is wasted.