Should I be concerned?

My August baby has been exhibiting some concerning behavior. He thinks it's funny to hurt animals - the dogs, the cats.. if we don't watch him close he will try to poke them with objects, kick them, pull their fur, etc. and laugh. I've been discipling and trying to explain for around a year now that we don't ever hurt animals under any circumstances.

Aside from that, he will also make comments like:

-I shoot those dogs.

-I cut that bad guy with a knife.

-Pow, pow (while making guns with fingers)

There is absolutely no violence in our house and this makes me so sad and worried. I'm guessing he learned to say these things at daycare, but he hasn't attended in two months and it is still continuing.

Would you be worried or will this pass? My worst fear is raising a child who will grow up to be a bad person. We give him plenty of love, support, and attention and I can't seem to get this under control. He is a VERY strong willed and smart child. He's been using complex words and forming long sentences since he was around 18 months old. He doesn't forget anything.