More Wildlife
One of the highlights of Destiny 2’s reveal was Cayde-6 shrugging off some alien/beast/dog thing that tried to tackle him. In the current entry to the series we’ve only faced the alien races themselves along with a few machines like Spider Tanks, Shanks, and Servitors. We’d yet to have seen any actual beasts from other planets, heck not even any on Earth. Seeing a beast actually charging at a Guardian was actually pretty cool.
Having wildlife like the above beast would add some much needed diversity to the enemies you face while also adding some life to the worlds you’ll undoubtedly traverse. Sure the Cabal, Fallen, Hive, Vex, and Taken were cool in their own ways, but you still essentially shot enemies who were busy shooting back at you. A wild element will shake things up quite a bit.
