ZOMG is OMG with a sarcastic twist. Logan and Jacob were really tired and nothing made sense so they said ZOMG (a typo at the time) was OMG but sarcastic
The more recent form of the acronym "OMG", which means "Oh my god."
The Z was NOT a fucking mistake...
An ever so famous Loot Ninja, that originated from the realm Dunemaul on World of Warcraft, always ninja'd shit and so people would say "ZOMG", meaning Zode oh my god.