Throughout history there have been countless sightings of mysterious creatures, from gators in the sewer to the Snow Beast of the Colorado Rockies. HISTORY brings science and technology to bear on these creatures of legend and seeks confirmation of their existence. Each episode examines the best evidence available, from pictures and video to actual eyewitness accounts. From pilots to policemen to ship captains, a number of seemingly credible people have seen things they can't explain. One part history, one part science and one part monsters, MonsterQuest discovers the truth in these sightings, and the legendary creatures behind them.