Avengers: Infinity War - 35 Easter Eggs & References Explained

18. The Return Of The Chitauri

Despite the fact that Loki led them to their defeat and apparently total destruction in The Avengers, the Chitauri - Thanos' hired army of cannon fodder - make their grand reappearance in the flashback scene establishing how Thanos "adopted" Gamora.

We see them invading her home planet the same way the alien race invaded New York, including deploying their giant space woodlice flying machines and it's the foot-soldiers themselves that kill half of Gamora's people at the behest of Thanos. By the time Thanos reappears in the present, they've been replaced by the Outrider army from the Infinity comic book arc.