16 month hitting

Let me start by saying my son is the sweetest nicest boy ever I know everyone says that but he truly is but lately he has been hitting the dog a lot and or me. behavior I think he learned from a boy at daycare, like last night when we laid down for bed he didn’t want to sleep so he kept like play hitting me not like mad or anything but I think he knows it bugs me so he thinks that’s funny I try telling him no no owie a term he knows well and knows what it means and I try telling him that’s not nice and hurts me. Or the dog he looks at me and listens sometimes he’ll stop others he laughs and thinks it’s a game and does it again over and over I’ve tried showing him how to pet the dog and say nice when we do that and he smiles and pets nice but then 5 mins later does it again so I guess I need some help what to do (I’m very against spanking or any physical punishment so please don’t suggest that) thank you