Welcome all to a new series of tips, tricks and advice that may help you design/redesign a character. Please note Firstly I am NOT a professional, im just forwarding my observations!
First tip is accociated with shape language.
Generally speaking, characters of any kind have one dominant shape depending on what they are trying to portray. Circles as a general rule are seen as being very fun and bouncy shapes, some good examples are Mickey mouse(Disney), Mario (Nintendo) and (My own) Beebo.
Squares are generally seen as being sturdy, strong and dependable, some good examples are wreck it ralph (disney), The hulk (Marvel), and (My own) Kamzez97.
Triangles are often accociated with speed, or danger, such as Sonic (Sega), Melificent (Disney) or (my own) Bathazar.
There may also be a mix of shapes integrated into the design to portray different messages, an example is Fifi, She mostly uses circles in her design as she is super fun loving, energetic and bouncy. However she does utilise elements of squares to portray her durability.
The key thing however is that one shape type is dominant!
If you have any further questions feel free to post them in the comments below!! Ill answer them the best I can!