Fathom

Fathom is a Decepticon Titan Master from the Titans Return portion of the Generation 1 continuity family.

Don't call him Fathorn.

Fathom grants the power of armor crush to his partner Tidal Wave.

Fiction

Titans Return marketing material

Fathom was presumably present with Tidal Wave as his larger partner fought against the Autobots on Cybertron.

Toys

Titans Return

• Siege on Cybertron (Gift set, 2017)

Fathom is a redeco and retool of Titans Return Sovereign, having a different robot mode "backpack" for the head mode face. Fathom transforms from a robot based on Safeguard into Tidal Wave's head, though he can also form the head of any Titans Return Deluxe, Voyager, or Leader Class figure.

Fathom and Tidal Wave were only available as part of the "Siege of Cybertron" set, which also includes Magnus Prime & Ginrai, Professor Go & Metalhawk, Decepticon Pounce, and Thunderwing. In the United States, this set was exclusive to BigBadToyStore, but it saw a wider release in Canada where it was available at Toys"R"Us, Amazon, the Canadian Walmart online store, book store chain Indigo and several PC retailers (seriously!). Additionally, it was also available at retail in Hong Kong and Singapore and even saw an official in the Netherlands, where it was exclusively available from BOL.

• More information on Fathom at Transformers-Universe.com

Notes

• Fathom is not named anywhere on the "Siege on Cybertron" packaging materials. Rather, he, Ginrai, and Professor Go were named months later on the Trypticon's Titan Master Crunch poster distributed by Hasbro at San Diego Comic-Con 2017.
• As a redeco (other than the new Tidal Wave head) of Sovereign, Fathom has a particularly weird design lineage, since Sovereign was designed to resemble Fun Publications' BotCon 2007 exclusive Beta Maxx figure, itself a redeco of Cybertron Safeguard.