Hey. I've played with the Egg of Quango against 3 different people, and they all said that the term "hits" means I have to roll to hit. I compared this to magic missiles and how it also says hits, but they didn't agree. Every time I use it the people in charge of rules make sure I roll to hit and don't just roll for wounds. Do the hits auto hit?
You only need to roll to hit if the wording of a rule says "attacks" or "shots." "Immediately suffers X Strength n hits" means the hits are automatic. You only need to roll to wound (and they need to roll for saves.)
Scalenex is correct. It's classified as Unusual Attack (BRB pg. 42) and effectively works the same way as a Breath Weapon in close combat. The people you are playing against must not be familiar with these types of attacks.