well this is not a JOKE so be careful
it can be dangerous
but if used properly it can be a great fun as well
i will provide you a simple design but you can go for complex one as well and yeah it run on small red cracker used by children.

Step 1: Materials

as usual like in my other instructable i will explain you the material which are cheapest alternative.
PVC pipe having 1 inch diameter
but thick enough so that only a red cracker can be placed inside it.
a drill to make hole or you can use screwdriver as i myself used it.
M seal or stone small enough to fit in the pipe
red crackers and match stick or lighter

Step 2: Making Canon

to make a canon you need to cut a pipe piece big enough to fit a red cracker and stone length wise and have a space of 1/2 inch left.
make a hole at one side leaving a space of .25 inch from end.
make sure that the hole is large enough to make the burning part of cracker out but not too large that the cracker comes out.
NOTE ~
you may need to increase or decrease the size of hole as per performance so you can make it small but not big.

Step 3: Making the Throwing Part

to make the throwing part you can use a stone if you have ample of them and you are playing out side.
if you are playing inside and have a aim then you can make round one as it has better stability.
so mix the M seal and make round balls big enough to easily pass through canon.
let them dry.

Step 4: Making a Base

to make a base you need a tray and fill it with sand.
to make, it aim towards the target and press in the sand or you can make a base and explain me as well.
NOTE -
I do know how to make complex ones but I need simple and better one.

Step 5: Loading

to load the canon you need to pass a cracker and take out its burning thing out from hole.
press from the front to make make it completely out using stick.
now place the round M Seal.
place inside sand and aim.
fire in the hole !!!!!!!