Q: If someone plays Beam Us Up, and one player had a being/crew member with a Creeper attached, what happens? What if someone has the Teleporter/Transporter?

A: The Keeper and Creeper would get sucked up into that person’s hand… but a Creeper can never be in your hand, so the Creeper is then immediately played back to the table by that player. It would either then reattach to some other Keeper if possible, or hang around for as long as it takes for a new Keeper of the right type to show up to attach to.

Once you understand what’s happening with Beam Us Up in the normal case, you can figure out what will happen if someone has the Teleporter or Transporter in play. The Creeper won’t be left behind with the original owner, it is attached to the Keeper which is Beamed up, and when taken up into that person’s hand it’s then “spat out” in front of that player… not the person the Crew Member was taken from.