The Black Triangles are the villains of the first segment, Symphony No. 5 in Disney's 2000 animated film, Fantasia 2000. They are a group of triangles as their names imply to represent darkness and evil.
They are dark abstract shapes which resemble bats and are the nemeses of the Colorful Triangles. Soon as darkness spreads across the light, the Black Triangles emerge from the ground and try to take over the skies as they prepare to block the sunlight, chasing their nemeses as the large orange triangle and the small pink triangle prepare to rescue them from the Black Triangles. One triangle attacks the large orange triangle as and is unable to follow small pink triangle because it was injured by one of them. The small pink triangle encounters the other Colorful Triangles as they look for light in order to get rid of the Black Triangles. Later during the end of the segment, they are shattered by the power of the sun as the Colorful Triangles fly upwards to the sunlight.