Get a cap full of blackpowder (can get it from walmart)
Lots of styrofoam
Lots of gasoline!!
1. Now lets poor the gas over the styrofoam to melt down the styrofoam (it is made from gas extract so breaks down when mixed)
2. Then once it is broke down put the cap into the mixture (somewhere in the middle) now it will be sticky and explosive.
3. Stick it to a tree or something and light it and run.
I reccomend making or getting a long wick. Otherwise you'll probably blow your dumbass self up.