The picture is actually a very realistic drawing of the common garden snail variety for the snail's body and the spiral shell. It is only once we add the large exaggerated cartoony eyes and a smiley mouth that we change the look and feel into a friendly, cartoony and really cute snail drawing.
Our snail drawing starts with the most recognisable part: the spiral of the snail's shell. Start nice and wide, and draw a spiral that tightens up into smaller and smaller curves. Notice the centre of the spiral is off to one side - the curves are tighter on the right with a larger gap on the left.
Next, draw the snail's head - and oval that transitions smoothly down to the back and joins with the spiral we have drawn in the previous step. Then join the top of the shell to the snail's back.
Do you know an animal with just one foot? Of course, you do - you are drawing it right now! Let's draw the snail's muscular foot next. Draw a wide and rounded letter "A" that joins to the snail's "neck". Then draw the small curve behind the shell that makes the top of the tail. Finally, close the foot with a wavy line at the bottom.
We have decided to give our snail large exaggerated cartoony eyes - let's draw those now. Start with two circles for the eyes well above the head. Then join the eyes to the head with two long eyestalks - just two widening-out sticks, closed by a small arc at the bottom.
As you can see on this detailed picture of a snail, a snail's foot has a bit of a noticeable edge - sketch it as a double-up of the wavy bottom line and curve it up to the shell edge. (By the way, that picture link has some really interesting facts about snails - so check that out).
Let's finish drawing snail's eyes: mark out the front of the eyes with two curves, and then add two small ovals in the middle of the eye for the pupil.
Then draw the second set of the tentacles - snails use these as feelers. On our cartoony version, we draw them sticking out like a moustache. To complete the cartoony snail face, add a nice smiley mouth.
The final detail to improve our snail drawing is to mark out the stripes on the shell. These are all slightly curved and get closer together as the shell twists get narrower. That is enough snail sketching.
Well, since we have done all the hard work while sketching the snail, the outline is going to be fairly simple. Let's draw the eyes, tentacles and mouth first - these are a straight outline of the sketch. Fill in the eyes, leaving the middle dots white.
Next, outline the front of the snail's body. Again, this is mostly a direct outline of the sketch, with just the front corner nicely rounded off.
Next, outline the snail's shell - both the outer spiral and the split stripes.
Finally, outline the snail's foot - again the only change from the sketch is rounding off the front corner.
Here is the final result of our "how to draw a snail" tutorial: the complete outline snail drawing after we have cleaned up the sketch lines.
This is actually a very realistic snail drawing, except for the extra-large cartoony eyes and the smiley mouth. It is interesting how adding just two small details makes the snail drawing cute and friendly.
And here is the snail drawing coloured in. We have used realistic colours if a bit saturated for interest: a yellow body with darker orange shading and a matching gingery brown for the snail's shell. And of course, the snail is crawling over some lush green grass - to add some contrast to the yellow.
And that is the end of the tutorial - now you know how to draw a snail!