Design and Target Audience

Turtles.

The design and look of these cartoon turtles varies by their animation type and intended demographic.

Octonauts

This turtle is generally round and soft, featuring plain colour and design he is a simple character.

Octonauts is aimed at young children so this character is definitely appropriate, they can easily understand what this turtle is.

Pokemon

Squirtle is a turtle from the Pokemon franchise, he is more detailed than the Octonaut, and has a distinctly anime style with his cute eyes. The target audience would be from roughly 10 or over so it fits with regard to the increase in detail from the last one.

Teenage Mutant Ninja Turtles

These turtles are what they say on the tin - teenage. Far more complex, tall and full of attitude they are pitched at young male teens. Mild violence is the name of the game here.

Adventure Time

Quirky but unusually simple, this turtle uses different earthy colours. It's appropriately targeted at young teens due to it's odd and funny aesthetic.