I was killing Chronozon, and I found a spot where him and the bouncers wouldn't attack you and you couldn't attack them. so I figured id wait for it to spawn there, and when it spawned, i lured it around, and this happened.

http://i.gyazo.com/9004e019fc2b2fbee5fd03d6fbc1a2b6.png

Obviously, I figured this was a bug s I told Vaughn about it.

http://gyazo.com/05ab380b867cf389a2c78ce03e05d82d

After that, I figured I'd see if I could figure out exactly how it happened, and I did.

http://gyazo.com/591afaadd75cb2388c8269be1a5a4c5b

90% of the time, both will spawn outside the map. The other 10% one spawns outside the map, and the other is spawned behind the wall, where it still cannot attack you, causing essentially the same effect.

I'd hate to see the results of this with range, if you lured him around behind the armor, you could easily safe-spot him taking no damage and not even using prayer potions, I haven't tested this yet, but if I do decide to test it, I will post more images of the results.