Toonami

Toonami is a programming block on Cartoon Network that specializes in action cartoons. Beginning life in 1997, Toonami has infrequently premiered numerous Transformers animated series ever since. Initially hosted by Moltar of Space Ghost fame, the block has been hosted by TOM (voiced by Steve Blum) since 1999, with Peter Cullen (referred to by TOM as "The Big Guy") narrating commercials and other promotions. One of Toonami's most popular attributes are its original opening sequences, crafted from clips and soundbytes of their respective shows and set to funky techno beats.

Beast Wars
Beast Wars was Toonami's first Transformers series, replacing The Real Adventures of Jonny Quest for a special week of premieres in 1998.

Promo: Moltar introduces Beast Wars as Rattrap sends Jonny Quest to a gruesome fate.

Armada
Toonami wouldn't see any Transformers action again until 2002, when it premiered Transformers Armada. The programming block having now moved to Saturday nights from its original wekday afternoon format, Toonami issued one new episode a week (save the premiere Saturday, in which the first three episodes were aired together as a "movie").

The Unicron Trilogy would be plagued by Cartoon Network's rather indecipherable scheduling logic, often times being moved off of the block and back onto it without any warning, making following the series a chore at best.

Energon
The next series to premiere on Toonami would be Transformers Energon in 2004.

Cybertron
Transformers Cybertron would be Toonami's fourth Transformers series, premiering in 2005. As a tie-in during the opening week of the live-action Transformers film, Toonami dedicated an entire night to a Cybertron marathon.