What's this about five different alien creatures from five different worlds?

We got a trio of new 'Alien: Earth' trailers last week, and one hints at alien 'monsters' that aren't the xenomorphs (video)

Source: space
Source Link: https://www.space.com/entertainment/we-got-a-trio-of-new-alien-earth-trailers-last-week-and-one-hints-at-alien-monsters-that-arent-the-xenomorphs-video