Character model
A Character model is a stylistic guide created to help animators and licensee artists depict the Transformers in a consistent and recognizable way. Most of the Generation 1 character designs were done by Floro Dery. The widely-distributed model sheets of those characters may have been redrawn from his designs, or they might be his direct work.
If the same toy is used for multiple characters, they may be depicted with very different character models. For example, Sideswipe and Red Alert. These two toys are essentialy identical, but while the first design conceived - Sideswipe's - is tall and athletic, the second - Red Alert's - is short and stocky. This pattern of artistically differentiating two very similar toys in order to make distinct characterization easier continued with Trailbreaker/Hoist, Prowl/Smokescreen, the Seekers/the Coneheads, and others.
Character models may vary wildly from the toy itself, perhaps most conspicuously Ironhide / Ratchet. In those instances, droid-like and "alien" toys were heavily anthropomorphized in the character models, adding humanoid proportions, heads, and faces.
Perhaps the best representation of both of the above factors--character models differing from the toys, and later character models differing from earlier ones based on the same toy--is shown by Tarantulas and Blackarachnia.
A vast collection of Generation 1 character models is available in the book The Ark: A Complete Compendium of Transformers Animation Models. Even more character models, including Japanese-exclusive series and alternate studio designs, are available in Transformers Generations, though its pictures are quite small.
