<Li> Mina Sundwall as 15 - year - old Penny Robinson . </Li> <Li> Ignacio Serricchio as Don West, ship's mechanic and smuggler of luxury goods . He is accompanied by Debbie, which he calls his lucky chicken . </Li> <Li> Parker Posey as June Harris, a criminal and psychopath who assumes the identity of her sister Jessica to take her place on the colony ship and subsequently impersonates Dr. Zachary Smith during the attack to take his seat on an evacuating Jupiter ship . After landing on the planet, Harris attempts to sabotage the colonists' chances of rescue by the Resolute, all the while manipulating and gaslighting other survivors to avoid prosecution for her crimes . The theft of the doctor's identity is a reference to the corresponding character of Dr. Smith in the original television series . </Li> <Li> Brian Steele as the Robot, an alien robot being that Will encounters following the crash . The robot has a different form from the ones that appeared in the previous series and film . </Li>

Who plays doctor smith on lost in space