Unicron's heralds in the comic were Galvatron, Scourge, Dirge, Thunderwing, and Bludgeon.
I remember Galvatron and Thunderwing. I also remember Scourge as one of Galvatrons lieutenants but not the others. Were they heralds in other sources other than G1 cartoon and comics? There was also the trio Hook, Line, and Sinker who Galvatron later destroyed.