Decepticons, attack

"Decepticons, attack" is the general order for an attack among the Decepticons. It usually signals the opening of hostilities or an order to begin a concentrated assault against their intended target, be they Autobots or organics. The order is usually given by the Decepticon leader, a designated mission commander, or whoever else is in charge.

The Transformers cartoon
As leader of the Decepticons, Megatron was the one who most commonly gave the order of "Decepticons, attack!", becoming one of his signature cries. Usually, however, this would be followed by an order of "Decepticons, retreat!" at some point within the next five to ten minutes.

Shattered Glass
During the noble Decepticons' plan to destroy the evil Autobots' Ark, the heroic Megatron gave the order of "Decepticons, attack!" once they were assembled. Just goes to show that the more things change, the more they stay the same.