SamSam: The Monsters Who Invited Themselves/The Invisible SamSam

Two episodes. SamSam thinks that his three best friends have come to his party in disguise. But in fact they are three real monsters who have gate-crashed and cause chaos. SamMummy and SamDaddy aren't paying any attention to SamSam. It's not surprising, they are too preoccupied with their own problems.