Bring the Anger

Bring the Anger (also known as #BringTheAnger) was a promotional event that lasted from mid-November to the end of December of 2019 to celebrate the 10 year anniversary of the first Angry Birds game.

UNICEF
The partnership with UNICEF (United Nations Children's Fund) was an event in Angry Birds 2 where the player base had to reach 10 million pigs popped by December 1st for Rovio to donate $100,000 USD to the organization. This event also ran in mid 2021 again at the same goal.

Rage Rider
The Rage Rider was an electric scooter that activated by the sound of the user's voice, so screaming was a must. Manufactured by Spin, there were only 100 made and were given to internet celebrities such as Dude Perfect, Mr. Beast, Tanner Fox and more. It is estimated that Rovio has kept at least 5 in their possessions throughout their studios.

Venting Machine
The Venting Machine (play-on-words for Vending Machine) was a promotional event held in Time Square, NYC on November 21th, 2019 that had special guest and former WWE Wrestler "Big Show" demonstrating the use of the machine. When a participant punches and shakes the machine enough, the machine gives the user a special gift, which can span from stress reliever toys to pins. This event was believed to last a single day however.

UNICEF

 * https://mashable.com/article/angry-birds-10th-anniversary-event-details
 * https://www.facebook.com/angrybirds/photos/we-did-it-you-did-it-together-weve-crushed-the-angry-birds-2-piggy-popping-goal-/10157924023019928/

Rage Rider

 * https://www.adweek.com/brand-marketing/angry-birds-anger-powered-scooter-10th-anniversary/
 * https://www.campaignlive.com/article/angry-birds-invents-rage-powered-scooter-2019-not-ready/1665536

Venting Machine

 * https://twitter.com/angry_facts/status/1380175824893136900
 * https://twitter.com/engadget/status/1196806440725417987
 * https://twitter.com/AngryBirds/status/1196806833282920448
 * https://twitter.com/i/events/1197710806412091393