Greetings @Kimstarz,
Thank you for your report and sorry for the inconvenience and the late response.
After investigating your report, we found a bug that applies for Normal and Shiny Chespin sprites. The bug is forwarded to our Artists, and hopefully, a fix is released in the nearest future.
However, our Artists confirmed that Toxicroak sprite is correct as it should. So, no changes will be applied to Toxicroak sprite.
We encourage you to report more encountered bugs in the future by creating a new thread in the Bug Resolution Center.
Regards,
AlGazawy