Using coloured pen and ink and other mediums

Today I experimented with some new inks I bought in London. I wanted to create a realistic looking tortoise using different mark techniques. I have used; coloured inks, black indian ink, water soluble pen, permanent pen, 2B pencil, water colour pencils and white gouache paint.

I like how it's turned out, but I don't know if it would work as a humorous drawing. I need to produce some more, maybe two tortoises mating to see if it would work.