These are a few selected pictures internet searches turned up underscoring Tsathoggua's artistic divergences:

This sinister version of Tsathoggua comes from renowned Lovecraftian artist John Coulthart. It emphasizes nearly bio-mechanical toad facets of the hideous god, and is by far the most orthodoxly Lovecraftian of the images selected. The creature's absolutely malevolent appearance and the ornamentation surrounding it closely correlates with Lovecraft's stern representation of Tsathoggua, as well as his correlation of it with the alien and ancient.

Although this drawing comes from Eldritch Dark, a website collecting art inspired by Clark Ashton Smith, it too is firmly in the Lovecraftian camp. Here, Tsathoggua possesses a heavily reptilian skin, tail, and general appearance. Only the bat-like wings and nose are truer to Smith's description, removing it only slightly from the vision held by HPL.

This piece, bearing an almost retro or New Age design, is from an amateur artist on Yog-Sothoth.com's forums. As with the Eldritch Dark depiction above, one would expect this work from Yog-Sothoth.com to appear more loyal to Lovecraft rather than Smith. This is not the case. Tsathoggua's furry body is clearly evident, along with a wide batty head. This Tsathoggua is unmistakably mammalian, and thus most in line with Clark Ashton Smith's original writing on the creature.
This lighthearted re-imagining of Tsathoggua is definitely Smith-like in its furry bat-like form, but also showcases the artist's own unique liberties. This Tsathoggua is not just mammalian, but anthropomorphized, something that doesn't appear in descriptions by Smith or Lovecraft. Moreover, its cartoony style and subtle humor place it closer to the realm of Cutethulhu than other more serious Tsathogguas.
-Grim Blogger