The Carlson's move into their new home but little do they realise there are monsters in the basement. How long can Eddie hide them from the rest of the family?
Eddie is panicking about the arrival of his school report, and tries to stop the post with the help of the monsters. But they are too busy being educated by Kate and Nick, who are desperate to prove who is the brainier parent.
Haggis is depressed and no one knows why. A therapist says he needs a father figure so Nick reluctantly steps into the role. But when Nick starts to enjoy his time with his new monster son, Eddie and the other monsters start to get jealous.
Eddie is convinced that his parents are splitting up and asks the monsters to help him stop his Dad running away. But the monsters are too busy reviving their singing group, The Fabulous Monsterettes, convinced that Angela wants them as her backing group.
When Eddie teaches the monsters about lying, little does he realise what he has unleashed. What starts out as a tiny fib soon escalates into a series of huge whoppers and Eddie has to play along with all of them for fear of being found out.
When Eddie teaches Haggis to be more assertive, things soon gets out of hand as the furry giant starts to throw his weight. Meanwhile Fiend is reduced to a gibbering wreck, now that Haggis has taken his role as the bossy monster.
Nick messes up his and Kate's wedding anniversary, she announces that he is not the man she married. So Fiend, Haggis and Norman kidnap him to find the 'real' Nick. Can Eddie and Angela persuade the monsters that it really is their dad?
When Angela's new-found friends bail out of her first ever sleepover, the monsters are only too keen to step in for some girly fun. But her fickle friends decide to turn up after all, and Angela finds herself trying to keep the two sleepovers separate.
Eddie and the monsters keep reading Angela's diary - obsessed with her day-to-day life. But when Angela finds out, she gets her revenge by writing entries she knows will freak the monsters out.
When the monsters scare off a cleaner, Kate reaches breaking point; either they clean up their own mess or get out. Eddie is desperate to tidy the house before she gets back but the monsters have other ideas.
When Angela is asked to babysit, the monsters ask Nick how babies are made. As usual, they get the wrong end of the stick and Haggis ends up thinking he's pregnant. But will Eddie and Angela persuade him that the baby's not his before the real mother comes back?
Eddie sneakily floods the basement so that Fiend, Haggis and Norman are allowed to live upstairs with the family. But his plan backfires when hanging round with the human's too long turns the monsters into very un-monsterly, civilised grown-ups.
When Eddie announces that he wants to become a full-time monster, his parents start to worry and encourage him to play with a normal boy. But when Eddie abandons the monsters to play computer games with his new friend, Fiend, Haggis and Norman create so much havoc that Nick finally snaps and dumps them in a forest.
Eddie pretends to be ill to avoid a maths test, promising the monsters they will have a great day hanging out together. But the monsters think they really have caught something - from Nick, who is at home, genuinely ill. So they make their own medicine which they test on Human Dad Thingy first.
The monsters become obsessed with all things shiny - especially money, the shiniest thing there is. So to get as much of it as possible, they set up a business in the basement - but what starts out as a bit of fun starts to go sour when the monsters turn into hard-nosed businessmen.
The Carlsons are all set to go on a dream holiday to Mexico - until Norman eats their passports at the last minute. But Eddie and the monsters persuade the family they don't need to go away to have fun, and they decide to have their holiday at home.
Norman turns into a human boy for just one hour and escapes from the basement - so Eddie and the others have to catch him before he barges in on Kate and Nick's dinner party upstairs. But worst of all, how do they stop Angela falling for this mysterious, gorgeous blue-eyed dream boy?
When Eddie goes on a school trip, the monsters are lost without their leader. So Fiend appoints himself king of the monsters. But Haggis and Norman each think they should be in charge, so they decide to hold an election.
When Kate wins a cookie competition, little does she know that some of Norman's fur went into the mix that won her the top prize. So when a film crew comes to film her making the famous cookies, Eddie and the monsters have to secretly get more fur into the dough.
The monsters are fed up with the family never having time for them, so they steal all the clocks in the house. In response, Nick installs a huge and terrifying grandfather clock - from now on, the house is going to run like clockwork! There's definitely no 'time' for fun anymore.
It's Eddie's birthday and he can't wait for a party with his three best friends in the all the world - Haggis, Fiend and Norman. But when the monsters argue over what present to give Eddie, it turns into a full scale row that threatens all the party plans, and even their friendship with Eddie.
When the monsters are impressed by a few of Dad's old magic tricks, Fiend decides to become a master magician. Of course, he is useless, and manages to chain Angela and Norman together - just as Angela has a date coming over!
When Eddie tells the monsters about swapping teeny pets - free toys that come in cereal packets - Fiend becomes addicted, determined to build the biggest collection of teeny pets ever. Meanwhile, it gives Kate and Nick the idea to swap roles - leading to even more chaos in the household.
When the monsters are left home alone while the family visit Kate's parents, they receive a surprise visit from a couple of burglars. The burglars get more than they bargained for as the monsters defend the Carlson house in true monster style.
Nick and Kate go out for dinner, leaving a new babysitter in charge. At first it seems Mrs Travers just wants to spoil Eddie and Angela's Friday night fun - but it turns out she is a monster catcher! How will they stop her from seeing the monsters - especially when Haggis thinks he doesn't exist and actually wants to be seen?
Eddie pretends to be ill to avoid a maths test, promising the monsters they will have a great day hanging out together. But the monsters think they really have caught something - from Nick, who is at home, genuinely ill. So they make their own medicine which they test on Human Dad Thingy first.
The monsters become obsessed with all things shiny - especially money, the shiniest thing there is. So to get as much of it as possible, they set up a business in the basement - but what starts out as a bit of fun starts to go sour when the monsters turn into hard-nosed businessmen.
The Carlsons are all set to go on a dream holiday to Mexico - until Norman eats their passports at the last minute. But Eddie and the monsters persuade the family they don't need to go away to have fun, and they decide to have their holiday at home.
Norman turns into a human boy for just one hour and escapes from the basement - so Eddie and the others have to catch him before he barges in on Kate and Nick's dinner party upstairs. But worst of all, how do they stop Angela falling for this mysterious, gorgeous blue-eyed dream boy?
When Eddie goes on a school trip, the monsters are lost without their leader. So Fiend appoints himself king of the monsters. But Haggis and Norman each think they should be in charge, so they decide to hold an election.
When Kate wins a cookie competition, little does she know that some of Norman's fur went into the mix that won her the top prize. So when a film crew comes to film her making the famous cookies, Eddie and the monsters have to secretly get more fur into the dough.
The monsters are fed up with the family never having time for them, so they steal all the clocks in the house. In response, Nick installs a huge and terrifying grandfather clock - from now on, the house is going to run like clockwork! There's definitely no 'time' for fun anymore.
Eddie pretends to be ill to avoid a maths test, promising the monsters they'll have a great day hanging out together. But the monsters think they really have caught something from Nick, who is genuinely ill. So they make their own 'medicine', which they test on Human Dad thingy first.
It's Eddie's birthday and he can't wait for a party with his three best friends in the all the world - Haggis, Fiend and Norman. But when the monsters argue over what present to give Eddie, it turns into a full scale row that threatens all the party plans, and even their friendship with Eddie.
When the monsters are impressed by a few of Dad's old magic tricks, Fiend decides to become a master magician. Of course, he is useless, and manages to chain Angela and Norman together - just as Angela has a date coming over!
When Eddie tells the monsters about swapping teeny pets - free toys that come in cereal packets - Fiend becomes addicted, determined to build the biggest collection of teeny pets ever. Meanwhile, it gives Kate and Nick the idea to swap roles - leading to even more chaos in the household.
When the monsters are left home alone while the family visit Kate's parents, they receive a surprise visit from a couple of burglars. The burglars get more than they bargained for as the monsters defend the Carlson house in true monster style.
Nick and Kate go out for dinner, leaving a new babysitter in charge. At first it seems Mrs Travers just wants to spoil Eddie and Angela's friday night fun - but it turns out she is a monster catcher! How will they stop her from seeing the monsters - especially when Haggis thinks he doesn't exist and actually wants to be seen?