Written by Robin French and Kieron Quirke, Cuckoo stars Andy Samberg, Taylor Lautner, Andie MacDowell, Greg Davies, Tamla Kari, Esther Smith, Tyger Drew-Honey, Helen Baxendale, Matt Lacey and Kenneth Collard.

In February 2014, it was announced that Samberg would not return for the second series, with Taylor Lautner replacing him as Cuckoo's long-lost lovechild Dale.

When Ken (Davies) and Lorna (Baxendale) collect their daughter Rachel (Kari) from the airport, they learn that she has returned from her gap year before medical school having married Dale "Cuckoo" Ashbrick (Samberg), an eccentric American hippie with an exuberantly loving attitude who does not have a job and loves to take drugs.

Two years have passed and Cuckoo has gone missing in a climbing accident in the Himalayas, Dylan (Drew-Honey) is planning to attend university, and Rachel (now played by Esther Smith) is moving in with new boyfriend Ben (Lacey).

Dale (Lautner), a bearded young American arrives, claiming to be Cuckoo's son and searching for his father whom he has never met.

Meanwhile, Ken and Lorna are preparing for the birth of their unplanned new baby, and their son Dylan (Drew-Honey) is getting ready to leave for university.

Series 4 was released, in full, online on BBC Three on 2 August 2018 with the opening episode titled "Lawyer of the Year".

[5] Series 5 introduces a new character, Ivy (Andie MacDowell), who comes to the UK from America with a slightly sinister plan.

Series 5 was released in full, online on BBC Three on 4 January 2019 with the opening episode titled “Ivy Arrives”.

Cuckoo is killed falling whilst 'rescuing' mountain goats in the Lower Himalayan Range in Nepal, oblivious to the fact that they were not in any difficulty.

Dylan is at sixth form college and is delighted to be accepted to take media studies at the University of Roehampton.

Lorna and Rachel witness a car hitting a 21-year-old man, Dale, who has an American accent, is naive and has no road sense.

Ken is trying to prevent him from joining another cult, concerned at him finding Hare Krishnas and Jehovah's Witnesses appealing.

Ken and his colleague Jane are competing for the position of senior partner, which is being vacated by Charles due to his retirement.

In response to Rachel saying that Ben is dull, the couple have sex in the stationery cupboard - unaware that there are CCTV cameras in the room.

Ken finds out about the sex session, so he goes to the office with Ben and Dale to take Charles' laptop to prevent him from seeing the footage.

Jane tells them that they do not know about CCTV footage, and that they are laughing about the sexual tweets he and Lorna sent each other, wrongly believing them to be privately sent.

When they arrive, Ken finds out that none of the rest of the group are there and is horrified when Jess gets him alone, tells him that her partner Marc does not exist, takes her clothes off and tries to seduce him.

Ken and Dylan cheer up when they attend a party which an attractive girl student, Charlie, invites them to.

Ken leads Dylan, Dale and another student, Nathan, to lift the supervisor's electric car onto an island in a lake.

Belinda drives from Spain in a 1976 Triumph Stag, a classic car which she inherited from Ken's father, Alan.

Ken is pleased to be nominated for Lichfield Lawyer of the Year; the ceremony - which also includes other categories - is run by Pegasus Alliance.

Ken is suspended from work for a month for unprofessional behaviour, damage to the reputation of the firm and using the awards ceremony to insult his colleagues.

Steve is attracted to her and immediately agrees to marry her, thinking he can turn it into a conventional marriage, even though she tells him that he cannot.

In the episode "Ken on E", Cuckoo sits reading a book whilst listening to "Shake Break Bounce" by The Chemical Brothers.

In "Lawyer of the Year", "Think I'm in Love" by Eddie Money play's during the opening dance number.

In "Opening Night", "Don't You (Forget About Me)" by Simple Minds plays in All Steve's Pals while Lorna tells Dale about Rachel's plans to move to Sierra Leone.

In "Trapped", a section from "The Number One Song in Heaven" by Sparks when Dale reveals to Rachel that he found out about her “pregnancy”.

In May 2015, NBC announced a US pilot of Cuckoo, starring Michael Chiklis, Cheryl Hines, and Flula Borg, was to be produced.

[3] UK writers Robin French and Kieron Quirke, who created the BBC series, wrote the adaptation with The Simpsons veteran Tim Long.