does it appear for any other match or team?
It appears only for every match of the said team .
Thunder (mascot)
"Thunder is friendly, and Broncos fans think it's good luck for the opposing team to pet our mascot". 
what is thunder (mascot)? A horse that is also an official live animal mascot. what is its duties as the last? The duties include leading the team onto the field at the start of every home game, and a gallop down the length of the field whenever the team scores a touchdown or field goal. which team are you talking about? The Denver Broncos Football Team.
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Thunder (mascot) [SEP] History
Magness said, "Thunder is friendly, and Broncos fans think it's good luck for the opposing team to pet our mascot". He was particularly popular with children, appeared on T-shirts, and was referred to as the "second most popular Bronco" after former quarterback John Elway. Thunder appeared at Elway's 1999 retirement gala. When team uniforms were redesigned in 1997, Thunder was the inspiration to incorporate a horse-head profile as part of the logo on the team's helmets. During a February 4, 1997 press conference introducing the new logo, the team president and the art director for Nike, creators of the new design, described it as "a powerful horse with a fiery eye and mane." The original Thunder, also known as Thunder Sr., was retired in 2004 after serving 11 years as the team mascot.