Subject Echo is an alpha series big daddy who greatly resembles bouncer, he has yet to appear in a story.
Subject echo is larger than average bouncers, his drill is not welded onto his hand, but is mounted on his arm and can extend over his hand. He is shown to be more intellegent and thinking than normal bug daddies, he has been shown to be able to control, and willfully use plasmids. Despite his differances frim normal Big daddies, he is still never seen fighting other big daddies or big sisters, or attacking sane citizens or Rapture.
He is considerably more docile than other big daddies, and can be approached by other citizens without attacking, though in battle he is relentless, and will hunt attackers down should they retreat.