I've hesitated on crocheting cat toys due to safety concerns. Claws may get caught in the threads of the yarn and yarn can be eaten and cause blockages. If you do crochet toys for them, I'd consider using yarn thats made of one solid thread rather than traditional yarn, like the velvet blanket stuff. I've seen small balls of thinner velvet yarn at dollar general before that might be perfect for it.

Also, don't give them the toys unattended, and always remember to throw them away the second they start unraveling or breaking. I worked at quite a few vets offices as an intern and a tech and saw many people come in with animals with intestinal blockages who were shocked because they never saw their pet eat anything odd. Hair ties, string, and parts of toys are big ones for cats to eat. Catnip inside may encourage them to chew or eat the yarn.

I know it sucks because you want to make cute toys for them as a way to show love, but unfortunately cats can be dummies. We still love them anyways!

I don't know about your cat but mine loves balls or anything small enough to toss around. you could make just like small spheres and fill them with catnip and such. maybe sew on some eyes and ears and a tail. tada ya got a spherical mouse lol.

I actually just made a simple ball yesterday (just learning basic amigurumi stuff recently), accidentally dropped it in the ground, and my cat immediately attacked it. Based on his frantic batting and chasing it around the room, I'd say a simple ball makes a great cat toy! 😅

Wonder if you could use something like a thin stocking/tight material (like you would to put those weighted pellets inside a stuffed object), fill it with catnip, and put it in the center of the ball along with the other stuffing? (I might have to try this out one day soon now that I think of it!!)

I've made a mouse and an octopus for mine so far and they love them both! I was able to put catnip and silvervine in them. The silvervine is for Little Bitty who doesn't react to catnip. If you're still looking, I'll link the 2 patterns I've used and some others I plan to make at some point. I think any small plush with catnip/silvervine would work, tho, tbh