The "Killer B's" was a nickname for a rotating group of standout players for the Houston Astros from about 1995 to 1999. The two constants in this squad were Craig Biggio and Jeff Bagwell.
Biggio and Bagwell were present for the duration of the "Killer B's" period, and each year standout players who happened to have a last name that started with "B" were included in the bunch. Some other members over the years were Derek Bell, Sean Berry, Carlos Beltran and Lance Berkman. Collectively, the team of Bagwell, Biggio and Bell had a Wins Above Replacement statistic that was remarkably high during their tenure with the team.