On February 14, 1967, farmer Claude Edwards of Tuscumbia, Missouri stepped out of his house to find a giant, metallic gray-green mushroom standing in his field. As he approached the object, he noticed several three-foot tall figures waddling around the structure. Moving closer, he saw that the strange beings were the same dark olive green as the mushroom-shaped structure-- which Edwards was now convinced was some sort of space craft. The beings had large black eyes-- or possibly goggles. Edwards wasn't quite sure. They also had black coverings over their snouts-- though whether these were parts of their bodies, or some type of breathing apparatus isn't clear.
He also saw that the mushroom-craft had a row of windows or lights along its base that oscillated in a myriad of colors.
Edwards watched the creatures trundle about under their craft for a while, swinging their arms all over. Eventually he grabbed two rocks, intending to use them to punch a hole through the craft to prevent it taking off. However before he could get too close he struck some sort of invisible force field around the penguins and their ship. Edwards flung his rocks anyway. One bounced off the invisible wall, while the second skidded over the top of the mushroom ship and landed on the ground behind it. The farmer's aggressive behavior apparently startled the little green creatures enough that they retreated into the "stalk" of their craft and quietly floated up into the sky.
Edwards never gives a clear description of what the space penguins' arms looked like. However, using his original sketch of the creatures as a guide, I've taken a little artistic license and given them flat, hand-less ribbon-like limbs.