Definitions by Mcbreezay.

reaking havoc

Causing chaos.
Being insubordinate, troublesome, whyling out.

A few of Pauls friends are going to the movies and reaking havoc.

Causing problems, or chaos.
Being insubordinate, whying/ wilding out. Acting out of character.

Trevon and Luke were reakin havoc this weekend, at the fair, now they're locked up.