The Coalition reveals yet another enemy type in the game through a short GIF on Twitter.
The Swarm Flock is a swarm (surprise!) of flying leeches. As per the tweet, these are going to be your worst nightmare. Players actually caught a slight glimpse of them in the games reveal trailer at E3 2018. If their movement is as unpredictable and dynamic as this short snippet suggest, then they may very well be a worthy adversary indeed.
Source: N4G PC Gears 5 Reveals New Enemy Type That Will Be Your Worst Nightmare