@Nathan1You almost certainly should check a trowel.  It is pointy and is very unlikely to be allowed in carry on.

You might be able to carry on small bear canister particularly if it was inside a backpack that was small enough to be allowed as carry on.  I doubt TSA will care about a container but the airline might count it as one of your luggage pieces if you carried it separately.  If it has food in it you would need to be careful that none of that counts as a liquid and be over the allowed carry on quantity.

Personally I would check it with it inside  my backpack and/or inside the duffel that contains my backpack.