Trivia: Both Richard Lawson and Beatrice Straight were approached to reprise their roles from the first film (as members of the paranormal team that helped the family and Tangina), both both had to turn down the chance. Lawson was busy on another project and Straight was reportedly quite ill at the time of the shoot, and didn't feel up to filming anything.
Trivia: Will Sampson, who portrays Tyler, had previously starred in "One Flew Over the Cuccoo's Nest", where he famously escaped the hospital at the end of the movie. There is a sly reference to that film here, when Steven briefly mentions the idea that Tyler is an escaped patient from a asylum.
Trivia: The "vomit creature" sequence and "Kane beast" creature were added to the film after Julian Beck, who portrayed Kane in his human form, passed away during filming after a long battle with cancer. The crew purposely made the vomit creature's face loosely resemble Beck's, and added Beck's face into the mass of faces on the beast in order to let the audience know that the creatures were meant to be the Kane character in different forms.
Trivia: The "vomit monster" that is seen waddling about on the floor before turning to look at Steve and Diane, was actually played by a triple-amputee named Noble Craig. Craig had lost both of his legs and one of his arms in Vietnam, and specialized in portraying creatures in films thanks to his unique body.
Trivia: Unbeknownst to the cast and crew, several of the skeletons ordered for the production were real human skeletons (as opposed to replicas). When this was discovered, some crew and cast members demanded an exorcism or cleansing be performed on set, as they had already been feeling uneasy on-set before learning this, and felt the real skeletons may have brought some unwanted spirits to the set. Co-star Will Sampson, who like his character was a real-life shaman, offered to return to set one night after everyone else went home in order to perform an exorcism ritual. Reportedly, the mood and feeling on set greatly improved afterwards.
Trivia: The floating chainsaw that attacks the car is a reference to Tobe Hooper, who had directed the original "Poltergeist." Hooper got his start filming the famed horror film "The Texas Chainsaw Massacre", thus the chainsaw attacking the family was put in as a reference.
Answer: He is in the first movie and is referred to as "The Beast." In this movie he is in his human form and he want Carol-Anne because he believes that she can lead him and his people into the light and crossover from this world to a better place.