According to Mike Dougherty, it's Behemoth.
From an interview with William Bibbiani for Bloody-Disgusting from 2019.06.01:
For example, one of the titans in King of the Monsters is a gigantic mastodon with human-like arms. [...] “That one is named Behemoth, so that’s a biblical reference, and he’s one of the few male creatures,” Michael Dougherty explained to Bloody-Disgusting. “Because they always tend to be insectoid or reptilian or some combination of the two, and I really wanted another big, furry creature that looked like it could have survived during the Ice Age.”
In an interview with slashfilm:
Q: Rather than make you go through all 13 names, is there a place fans can look them up?
Dougherty: Yeah, there’s a website, MonarchSciences.com. They’re working on it and obviously revealing it in layers to keep people intrigued.
Here's a link to that site, but as of yet, Behemoth isn't featured yet.