The Monitor informally known as "Bob" is the Monitor of Earth-0, also known as New Earth. Jason Todd gives him the nickname "Bob", so as to distinguish him from the other Monitors in reference. Like his colleagues, Bob believes in preserving the sanctity of the Multiverse, but unlike one of his peers, does not believe in murdering those who have violated the cosmic balance by jaunting from reality to reality.
Bob brings together the Challengers from Beyond in order to find the missing Ray Palmer, however when they finally find him it all turns out to be a lie as he begins to murder the residence of the Earth that Ray was living on. Solomon attempts to merge with Bob to create a more powerful Monitor, but it is discovered that the Monitors have become too different for that to be possible and Bob is simply killed.