Mattzilla puts on his nightvision googles on and his miner's lamp headlight and he seeks out the barbies hiding under the chair and tries to eat them. The barbies try to get help from ken, but he's busy hiding under the table and is no help at all. Then the barbies talk under the chair and they say, "HELP! KEN! KILL MATTZILLA!". Then Mattzilla uses a hair clip that looks like it has really sharp teeth and then Ken sets a brick under him and Mattzilla eats the brick but it doesn't do anything but then they try putting clothes over the bricks to disguise them in the hopes that Mattzilla will eat them and die of indigestion.
(the kid's verbatim description of how "mattzilla and the barbies" works)