Lamarr
Lamarr is Dr. Kleiner's pet Headcrab seen in Half-Life 2. She has been de-beaked and is completely harmless.
Appearences
Lamarr is seen at the beginning of Half-Life 2 in Dr. Kleiner's lab, and hides in the air ducts while Gordon gets into the HEV Suit, then reappears to interrupt the teleportation sequence, teleporting Gordon to random places and eventually alerting the Combine to his presence. Lamarr is also seen peeking through the door back into Dr. Kleiner's lab after Gordon and Alyx escape Nova Prospeckt. Lamarr is then seen at the end of Half-Life 2 as a post-credits scene where she falls from an invisible portal and jumps at the camera, which then sends the user back to the main-menu.
Lamarr is also seen in Half-Life 2: Episode Two where she climbs into Magnuson's rocket, and flew on it.