|Featured in||Sonic Adventure 2|
The Finalhazard makes its appearance in the Last Story, as the final boss of Sonic Adventure 2. After Shadow defeated the Biolizard, Sonic and Knuckles managed to stop the Chaos Emeralds, which stopped the ARK's crash course. Suddenly, the Biolizard uses Chaos Control, teleporting itself outside and fusing itself with the Space Colony ARK, forming the Finalhazard and resuming its crash course to Earth. The creature fused with the ARK in order to obtain power. Sonic and Shadow team up and use the Chaos Emeralds to transform to Super Sonic and Super Shadow.
 Boss Battle
The final boss battle takes place in space and Super Sonic and Super Shadow must defeat the creature within five minutes. To defeat it, Sonic and Shadow must hit the swellings that appear on different parts of the body. After each hit, you'll alternate between Sonic and Shadow, both starting off with 50 rings at the beginning.
For the first hit, the creature surrounds itself with nine pink eggs and he lauches it towards the character. After avoiding the eggs, quickly attack the swelling area.
For the second hit, the Biolizard will briefly launch one laser beam multiple times. Maneuver your way around it and attack the weakpoint.
For the third hit, it will launch one laser beam and following that, it will surrounded it self with many pink eggs, which the character must maneuver his way through to strike the weakpoint.
The fourth hit is similar to the third, except that it launches two laser beams.
At this point, the maximum ring count drops to 40 rings.
As for the fifth and final hit, the Biolizard will launch the 2 laser beams in erratic patterns, while simultaneously launching the pink eggs towards you.
After the final hit, a cutscene will play, in which Super Sonic and Super Shadow uses Chaos Control to stop the Ark permanently from crashing into the Earth. Unexpectedly, this costed Shadow his life, as he started to disappear afterwards.