From the Super Mario Wiki
Birdos are dinosaur-like creatures with large snouts, which first appeared as a recurring boss monster in Super Mario Bros. 2 as the only member of its species. The Super Mario Bros. Super Show! is the first source in which other Birdos appear. Other Birdos later appear in a growing selection of palettes as spectators in various Mario titles, starting in Mario Power Tennis, and later become playable characters in Super Mario Strikers, Super Mario Sluggers, and Mario Strikers Charged. They are sometimes associated with Yoshis, which also come in many colors, possess prehistoric physiology, and utilize eggs as projectiles.
Super Mario Bros. 2
Birdo first appears in Super Mario Bros. 2 as a boss character in many levels, serving the evil villain Wart. Birdo comes in three colors with slightly variated abilities: Pink Birdo shoots eggs from her snout, Red Birdo shoots eggs and fireballs, and Green Birdo shoots fireballs. In the NES version, Green Birdo also appears as gray in World 5-1 and World 7-1. Additionally, in the NES version, they do not wear their red bow, while in the SNES version and other subsequent remakes, they do, although colored orange for the red and green Birdos. In the original cast roll and some versions of the manual, they were mistakenly labeled as Ostros. Additionally, Super Mario Advance includes a robotic Birdo named Robirdo.
BS Super Mario USA interprets the Birdo variations as three distinct characters voiced by different voice actors, while in Super Mario Advance, the three Birdo variations instead speak with a similar voice, but differ in pitch and have separate lines each: Pink Birdo has the highest pitched voice, Green Birdo has the lowest of the three, and Red Birdo's voice is in-between.
The Super Mario Bros. Super Show!
Birdos appear in various episodes of The Super Mario Bros. Super Show! as part of the Koopa Pack. In "The Adventures of Dirk Drain-Head", King Koopa claims to keep his Birdos in cages lined with Baroness Blue Blood comic book pages.
"The Bird! The Bird!"
Birdos first appear in the episode "The Bird! The Bird!", where a female mistakes Toad for her baby, Cheepy, and unwittingly kidnaps him. On the way to rescue him, Mario, Luigi, and Princess Toadstool find Cheepy encased in ice and start a fire to thaw out the Birdo. Meanwhile, Cheepy's mother takes Toad out into the open skies and lets go, sending him into a free-fall. Rather than plummeting to his doom, however, Toad manages to land safely by using his cap as a parachute, after which the group returns Cheepy to his mother. She later repays the heroes by helping them stave off an attack by King Koopa, carrying Toad while he drops vegetables on the soldiers of the Koopa Pack, thus forcing King Koopa to retreat.
King Koopa first deploys Birdos in "Toad Warriors". In order to make money, King Koopa steals the vast majority of Car Land's spaghetti sauce supply, planning to sell it back at a very inflated price.
King Koopa assigns three Birdos to act as the guns of his three State Troopa cars by firing eggs at the Rebel Fort while perched atop the vehicles. After the Mario Bros. arrive, King Koopa decides to use the Thunder Birdo to attack the fort. Thunder Birdo is driven in on another vehicle, controlled by Mouser, where it proceeds to attack the fort with a gigantic, explosive egg. Afterwards, King Koopa uses normal Birdo fire until a rebel force, which include Mario, Luigi, Princess Toadstool, and Toad, leave the fort using a tanker full of spaghetti sauce as bait. During the chase that ensues, the three Birdos are defeated by Luigi's Bob-ombs after attacking Mario and Toadstool. After the two regained control, they see the approaching Thunder Birdo. The princess climbs on top of the tanker armed with a bag of Bob-ombs. When Mouser approaches, the princess hurls the bag into the snout of the Birdo. Thunder Birdo swallows the Bob-ombs, and their explosion defeats it.
"On Her Majesty's Sewer Service"
During the events of, "On Her Majesty's Sewer Service", King Koopa hires an enormous Birdo with dragon wings and a K emblazoned on its chest. King Koopa, Mouser, Tryclyde, and Koopa Troopa embark to rob Spy Land's Coin supply from Fort Hard Knox, but are pursued by Mario and Luigi in the Spymobile. King Koopa, after several failed attempts to destroy the vehicle, call for the Birdo to lift the Spymobile from the road. The Birdo deposits the brothers in King Koopa's lair.
"Escape from Koopatraz"
In "Escape from Koopatraz", King Koopa includes one in the jury for the trial of Mario, Luigi, Princess Toadstool, and Toad. The Birdo deliberates the decision with the three other members of the jury, until King Koopa threatens them with a Piranha Plant. They quickly condemn Princess Toadstool and her friends as guilty.
Nintendo Comics System
As seen in the Nintendo Comics System comics "Bedtime for Drain-Head" and "Betrayal Most Proper", after losing control of the Mushroom Kingdom, Bowser employed Birdos as castle guards. Mario battles these guards on two occasions. Under the delusion that he was Dirk Drain-Head in "Bedtime for Drain-Head," Mario entered Bowser's Castle to save Toad. After laying waste to a large number of enemies outside of the castle, a Birdo blocked Mario's path and shot eggs at him as he tried to enter the castle. However, Mario quickly picked them up and threw them back, defeating this Birdo similarly to the Birdo in Super Mario Bros. 2. The second encounter with Birdos occurs in "Betrayal Most Proper" as Mario and Toad attempt to rescue Wooster, who are then attacked by Birdos in Bowser's Castle. When their movement becomes impaired by a conveyor belt moving in the opposite direction, the Birdos begin firing eggs. Rather than defeat the Birdos, they simply run off.
Mario Tennis series
Birdo made her sports debut in Mario Tennis, specializing in speed and able to have Daisy or Yoshi as a doubles partner. Birdo and Yoshi also share a themed court together, which is unlocked by winning the Star Cup using Birdo in doubles, and favors fast and tall players as the court itself is slow and bounces the ball high. Many different colored Birdos appear as background NPCs in cutscenes in Mario Power Tennis for the GameCube, most notably the red Birdo in Bowser's trophy acceptance cutscene.
Mario Strikers series
Soccer is the one sport in which a substantial number of Birdos participate. In the original Super Mario Strikers tournaments, teams of Birdos can be selected by certain high-profile captains to help them achieve victory. When compared to the other species involved, members of the Birdo species are the most aggressive, scoring the hard hits against opponents necessary in the sport. The events are also a huge draw for Birdo spectators.
In the sequel, Mario Strikers Charged, multiple Birdos compete as sidekick players, this time breaking away from all-Birdo teams and playing alongside other species. Birdos once again appear as one of the many species filling the stadiums.
The following is a list of Birdo colors appearing in Mario Strikers Charged.
Mario & Sonic at the London 2012 Olympic Games
Birdos as well as the character Birdo appear in Mario & Sonic at the London 2012 Olympic Games. In the game, multiple differently-colored Birdos serve as goalies in the Football event and a partner to Birdo in the Badminton Doubles in the London Party mode.
Aside from the Mario Strikers participants, the character Birdo is known to participate in many sports competitions, and has done so for Mario Golf: Toadstool Tour, Mario Kart: Double Dash!!, Mario Superstar Baseball, Mario Hoops 3-on-3, Mario Kart Wii, Mario Super Sluggers, and Mario Golf: World Tour, and has even participated in the London 2012 Olympic Games and the Sochi 2014 Olympic Games. Birdos return as goalies in Football and Duel Football in Mario & Sonic at the Rio 2016 Olympic Games, and are teammates for Princess Daisy in Football in the 3DS version.
Peaceful Birdos have made appearances in the audiences of many sports and racing games. They first appear at Peach Dome in Mario Power Tennis, and later attend Mario Stadium in Mario Superstar Baseball. Their most recent appearances are in the stands of various tracks of Mario Kart Wii, Mario Super Sluggers and Mario Kart 7. They reprise this role in Mario Sports Mix, in which they can be seen splashing in pools and waving in the background of some courts such as Koopa Troopa Beach, Daisy Garden, and Bowser Jr. Blvd.
In Super Mario Chess, Birdos appear as knights on Bowser's team.
Birdos have a rounded, white belly, tail spikes, and spots on their cheeks. They have purple eyes, each of which is framed by three long, thin eyelashes. They do not have hair, and instead wear a big red bow atop their head, which is usually their emblem. They have small but pointed claws, with four fingers on each hand and three toes on each foot, the latter also having white pads. More recently, a large diamond ring set in gold is occasionally depicted on their left hand. Birdos commonly wear eye makeup and large bows on their heads.
Official bios and stats
Super Mario Strikers Information
Mario Strikers Charged