Brett Favre 6,300 completions
As of the start of the 2008 season, that would be Brett Favre with 5,377.
Brett Favre, who holds virtually every career record for a quarterback, had 6,300 lifetime pass completions.
Ben Roethlisberger holds the Steeler record for most completions in a season with 337 in 2009.
As of Super Bowl XLII, that would be Joe Montana of the San Francisco 49ers with 13 consecutive completions in Super Bowl XXIV.
Dan Marino holds the record for passing yards in a season with 5084 in 1984.
Ask the dogs