It seems that all the amateur zoologists out there who saw the last teaser video from Mopar were correct and the elephant in the room is a Mopar Supercharged 426ci. V8 originally named the elephant engine.
The theories were confirmed with the release of the second teaser video below, with the only reasoning behind featuring an elephant in the video is either for the 7L/426ci crate engine or somebody at Mopar really likes those tusked animals. A Hellcat create engine was revealed at the 2017 SEMA show to much success. So, it looks like they are following this train of thought with further top crate engines.
There are no stats. to go along with the engine as yet, but you only have to wait until October 30th at 4:26 p.m. PT/7:26 p.m. ET, then go visit cratehemi.com for all to be revealed.