This is a Hawkgirl animation cell from the Super Friends show. From looking at the pose, I can certainly say it is from the short "The Crude Oil Monster" which also starred Aquaman and Hawkman. However, the background is all wrong; the story takes place in the ocean (Alaska, I think); so this cell is a fake. Someday, when the Super Friends episodes are available on DVD, I will revisit this post and prove how right I am. Until then, enjoy!