Trust me, animals are hard to draw. Can I give you some constructive criticism? I'll put it in a list.
It looks like you did this in MS Paint. When drawing in MS Paint, you should use the Pencil tool and not the Brush tool- it looks so much better.
Try using a better art program, maybe one with layers. I use Medibang Paint Pro. Despite the name, it's free!
Put a bit of a "structure" under your art- I'll upload something when I get home that will show what I mean by this.
Use references! This has helped me immensely in drawing, and I'm sure it will help you too.
Don't forget you have an eraser- I can see many messy lines that would be improved immensely by using an eraser.
There's no harm in using the circle tool when you're starting out. I consider myself a good artist, and I still use the circle tool as a base for heads and other stuff that requires circles.
Otherwise, though, it looks great! Practice makes perfect!