Animals.

After witnessing the unintentional death of a hooker by the mayor, two rats named Mike and Phil attend a party where it is discovered that Phil has never made babies while Mike raises his newborn daughter Rebecca as she grows into an adult over the course of the party. As Phil falls in love with Rebecca, he learns that he ate rat poison and spends his final moments finally having sex with Rebecca raising their son Phil Jr. Meanwhile two police horses, voiced by Paul Scheer and Matt Walsh, discuss a friend who has become a race horse; also two bed bugs voiced by Mark Duplass and Rob Corddry, move into the mayor's pubic hair and talk about one of their divorce and subsequent midlife crisis.

As the mayor deals with a blackmailer who took pictures of him with the hooker, unaware that one of his goons is an undercover detective, a golf ball hits a sleeping Phil's nest as he believes it to be an egg he laid. He joins his friend Mike and Mike's wife Megan to their son Jacob's Little Flyers Club where Mike is challenged to race to the Green Lady with the Ice Cream Thingy by Jerry, a pigeon from New Jersey, voiced by Nick Kroll. Meanwhile two caterpillars named Alan and Brian, voiced by Ike Barinholtz and Zach Woods respectively, deal with one of their metamorphosis.

As the mayor's wife is having an affair with her husband's opponent in the upcoming mayoral campaign, her pet cats Mike and Phil discuss their plans for the day when they are interrupted by an alley cat at the window named Alex, voice by Eric André. Mike and Phil let Alex in to use the kitty litter and give him a tour of their apartment where he steals various things. But when Alex comes clean after how friendly his hosts are, he learns that Mike and Phil are crazed sociopaths and barely escapes being tortured by them. Meanwhile, a goose named Shane, voiced by Adam Scott, explores Central Park and meets a swan named Olivia, voiced by Molly Shannon, who is led to believe that Shane is a Black Swan. His secret is found out later at a club and has to come clean.

A Papillon named Phil is taken to a dog park, which is viewed as a prison by the dogs in it. Phil is challenged to a showdown by a poodle named Angela, voiced by Chelsea Peretti. Phil and a pug named Mike plan an escape to avoid the showdown. Meanwhile, a secret is revealed among four dogs being walked also; two dogs, Rusty and Princess, meet on a first date, voiced by Kumail Nanjiani and Ellie Kemper, respectively.

As the mayor covers up the death of a business partner who overdosed, a teenaged Phil Jr. takes credit for the pants that his friend Mike invented to impress a girl he has a crush on. Meanwhile, two moths, voiced by Duncan Trussell and Kate Berlant, talk to their friend Kevin, voiced by Pete Holmes, as he tries neon light for the first time while a fish couple, voiced by Thomas Lennon and Kerri Kenney, argue in front of another couple, voiced by Mary Holland and Tim Baltz, during dinner, causing a tense situation.

Pigeon Phil runs into trouble after being reunited with the father who abandoned him while Mike struggles to encourage his son to be a seagull scout. Meanwhile, two turtles fight over the love of a mechanical frog while a skunk learns the truth about his date's past as a sexual deviant.

Within the course of a day, a pair of flies experience the highs and lows of life in all its stages; a self-conscious horse is encouraged to let it out; bodega-dwelling cats rap.

The mayor attempts to smear the politician by planting drugs in his house. But as all hell breaks loose when the mayor learns the politician was sleeping with his wife, two squirrel brothers find their survival skills tested while on a journey to freedom after their tree was knocked down by lightning. Meanwhile, at a pet shop, a snake and her mouse prey face off while pet store puppies settle a turf war.