I’m pretty sure the packaging that came with our de-shedding brush had some blurb on it about how grooming your cat can be a relaxing and bonding activity. I’m still waiting to see if it ever gets relaxing, but we sure do have fun.
My theory is that Grendel thinks the brush is “attacking” her because she behaves just like she would if she and Fafnir were play fighting. She flips onto her back, keeps her feet up and ready to repel me, and I have to rely on my agility to get any fur off of her (and take it off the brush before she can eat it).
Thankfully, she rarely unsheathes her claws when she’s play fighting with us. Even if I stop and let her run off, she usually comes stalking back over in a minute or two to attack the brush again. So I guess she likes it?