Bullcow

-Compared to other dark elixir troops, Bullcows attack in a straight path, charge while attacking and have a rare chance of destroying the first object in its past.
-For a great attack strategy Bullcows go great with basically anything that attacks from a distance and any troops behind the Bullcow.
-finally if you do not want to be destroyed by the Bullcow here is what you can do
place spring traps wisely
Use any Splash damage defenses you got
Use Giant Bombs
Flying units in clan castle
And inferno towers.