Well we currently have 4 Confirmed Gargant types; Kraken Eater, Warstomper, Gate Breaker and the Aleguzzler.
At the end of the Sons of Behemat teaser we saw what could potentially be a 4th new Gargant type.
I believe this could be a dual kit much like the Dankhold Troggoth/Troggboss. I think that this kit will have the option of being built as King Brodd, a leader or as another larger Gargant. This larger Gargant could even be a replacement for the Forgeworld Bonegrinder Gargant.