Tikal the Echidna

Tikal the Echidna (ティカル・ザ・エキドゥナ Tikaru za Ekiduna?) is a character of Sonic the Hedgehog series. She is a echidna from of games released by Sega. She first appeared in Sonic Adventure for the Sega Dreamcast, which was released in Japan on December 23, 1998.

Sonic Adventure
One of Tikal's abilities in Sonic Adventure is the ability to transport people to the past in their mind (similar to a vision), which affects the plot of the game. With it, she is able to show Sonic and his friends her past and try to persuade them to stop Chaos from obtaining the seven Chaos Emeralds (notably, Tails finds the Rhythm Badge in his vision, and still gets to use it in the present). Tikal is also able to turn into a floating red and white sphere of light, which enables her to quickly go to different places where Sonic and his friends are located. She can also communicate with Chaos, which allowed her to mollify his anger by telling him that the Chao are fine. She also seems to be able to teleport herself and others, like Chaos. Presumably, this may have been a use of Chaos Control or simply passing on.

Sonic Adventure 2 Battle
Tikal is an unlockable character in the Dreamcast game, Sonic Adventure 2 and its remake Sonic Adventure 2: Battle. To acquire her, the player has to complete all of Knuckles the Echidna's missions with an 'A' rank. She is then available to play in 2-player in the treasure hunting game as well as in the kart game. In the GameCube remake Sonic Adventure 2: Battle, she is initially playable in Treasure Hunting. Sonic Adventure 2 reuses several quotes from Sonic Adventure rather than using new lines from Tikal. Some people believe that her appearance in 2-player clears up the plot hole of her disappearance, while others think SEGA put her there for fans.

Other Games
Tikal has appeared rarely as a playable character, but she did show up in the now discontinued endless runner title, Sonic Runners, where she was a Fly/Wild type runner that was available only on the premium roulette.

She also turns up as a playable character in Sonic Forces: Speed Battle where she is a super rare character with the ability to summon Chao guardians to protect her or use a light energy similar to the form she took in Sonic Adventure to trap opponents.

Trivia

 * Tikal appears as a Mii costume in Mario & Sonic at the London 2012 Olympic Games, Mario & Sonic at the Sochi 2014 Olympic Winter Games and Mario & Sonic at the Rio 2016 Olympic Games.