Steel Leaf Champion has got a new partner in crime -- Nullhide Ferox. This creature is just as big and as dangerous as it can get. On top of that, it has Hexproof, which makes it even stronger.
Nullhide Ferox can be safely played in Green Stompy decks with a couple of variables.
Play it alongside Vine Mare and Ghalta, Primal Hunger. You can use Assassin's Trophy to remove unwanted blockers and keep hitting opponents with your giant beasts.
You could also make it work in a more midrangey deck alongside Shalai and Lyra Dawnbringer. But probably the best way to use Nullhide Ferox is in combination with Goreclaw, Terror of Qal Sisma, which will make it cost only two mana.