Crack-a-lackin', like snap, crackle, poppin' your ammo off
Referencing the mascots for Rice Crispies breakfast cereal
“Crack-a-lackin” is slang for get it going, get it out of control. “Snap, crackle, poppin' is a string of onomatopoeias to describe the sound of gun shots being fired. The reference to the Rice Crispies reinforces the reference. People are now shooting at him, the "Kraken” or monster that is now lose.
But from a figurative perspective, ammo being shot at the monster (kraken/Earl) are negative critiques of the lyrical beast.
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