Reference article
Fire Duck (Duck Life 4 Classic)
Frank, introduced as the Fire Duck, is the undefeated champion who lives inside the volcano and becomes the final opponent.
Story
One year after genetically modified ducks were banned, the Fire Duck reigns supreme. His name is Frank; this game introduces him as Fire Duck.
Calling him out
Win the three key races, unlock 
Mystery Box and activate the detonator. The eruption brings the angry champion out of the volcano.
Facing the champion
Enter 
Fire Duck’s Final Race after training the five racing skills to level 150. The entry requirement excludes energy.
After victory
The player receives the champion’s crown, a mysterious egg and access to arcade play.
Fire DuckThe Fire Duck, also known as Frank, is the champion in Duck Life 4 and returns as the final opponent in Duck Life 9: The Flock.