Aggressive 9 month old 😅

My nine month old is sassy and aggressive!!!! He hits and growls. Not sure if this is normal behavior for this age or what.. He doesn’t go to daycare ( he is with grandma while my husband and I work ).. I was just thinking where the hell he learned this from?? He’s our first babe so obviously no older siblings and with covid it’s not like he gets any play dates.. 😅 my husband and I don’t get aggressive towards each other lol. I do “get after” my dog when he isn’t listening??? (As in tell him no to barking or lay down in a stern voice.) then notice my baby will be watching and then growl like he’s copying me yelling at the dog.... 😅

I do tell my baby “no, be nice” When he hits me but he growls and hits again. Or pulls my hair.. or my shirt aggressively 😅😅😅😅 I worry about this.. but dang what more can I do? He also started arching his back and throwing a fit.. but that bothers me less than the purposeful hitting and being aggressive.