Dopey is the only dwarf who does not have a beard. He is accident-prone and mute, with Happy explaining that he has simply "never tried" to speak. He is like Gideon the Cat in Pinocchio, the title character as the circus elephant Dumbo, and Tootles in Peter Pan.
In the very early stages of pre-production for Snow White and the Seven Dwarfs, Dopey was simply called 'The Seventh'. An armature of each dwarf was constructed as reference for the animators. Perce Pierce, one of the storymen working on Snow White and the Seven Dwarfs, was particularly active in creating the characters of the dwarfs. Dopey's personality and role were finalized quite late in the process. After someone suggested that Dopey should move like burlesque comedian Eddie Collins, Collins himself was filmed performing actions for Dopey. This helped to define the character's personality. Mel Blanc, known for his voice work in Looney Tunes was hired to voice Dopey, but he was dropped when Dopey was decided to be mute. A similar event would happen with Gideon from Pinocchio.
Animation
Though designing the dwarfs was relatively easy, animating them proved to be difficult, as the animators, already finding human figures difficult to animate, now had to animate "ill-formed" human figures. Vladimir Tytla noted that the dwarfs should walk with a swing to their hips, and Fred Moore commented that the dwarfs had to move a little more quickly to keep up with the human characters.
In order to establish Dopey's character during the march home in "Heigh-Ho", George Stalling noted traits specific to the character, to be taken into account in the animation: An armature of each dwarf was constructed as reference for the animators.
Personality
Dopey is often the butt of the other dwarfs' jokes and his silly, playful actions often annoy the pompous Doc and the short-tempered Grumpy. Not entirely dim-witted, Dopey simply acts in the vein of a toddler or a dog, which explains why his shenanigans are met with little to no punishment or confrontation, aside from a soft clunk on the head, or something along those harmless lines. The dwarfs are apparently used to his goofy actions and simply ignore them, generally.
Perhaps Dopey's most notable trait is his lack of speech. As mentioned above, Happy states Dopey is simply unaware whether or not he can speak, as he has simply never tried. In spite of this, he can occasionally be heard making various vocals, such as whimpers, hiccups, and a one-shot yell. Interestingly, his lack of speech does not seem to trouble the rest of the dwarfs, as they are shown to understand his other forms of communication just fine. Doc, specifically, was able to easily translate Dopey's blathering into a cohesive sentence prior to their first meeting with Snow White.
Physical appearance
Snow White and the Seven Dwarfs
In the 1937 film, Dopey is a short and slender dwarf. Unlike his companions, he has no beard and is completely bald. He has pale skin, baby blue eyes, giant ears, thick black eyebrows, and a small pink cherry nose. He dons a loose olive drab turtleneck tunic with a couple of gold buttons vertically on his chest and sienna patches on his elbows stitched in black thread, a black belt with gold rectangular outlined buckle, blue leggings, a pair of sienna medieval-style shoes, and a purple stocking cap. He is also mute, according to Happy as he tells Snow White that he does not talk and never tries.