The red Giant Yoshi represents the T-Rex, a giant voracious dinosaur with a red color scheme.
The stage represents the arenas featured in the Fire Emblem series, a role-playing game similar to the Fossil Fighters series.
The Lava-Floor hazard references the T-Rex's Fire attribute, which specializes in fire-based attacks.
Other trivia:
This spirit's Attack type references the T-Rex's red color scheme and high attack stats in Fossil Fighters.
This spirit's Weight ↑ ability references the T-Rex's low evasion stat, being a large, heavywieght vivosaur.
