The website Scified has been told by a source that Ridley Scott's Prometheus sequel, which is now titled Alien: Covenant, will feature two monsters.
One of the two monsters will be new, though, both will have similarities to the classic Xenomorph. The new monster will be created from a new event and "it’s hinted that David (Michael Fassbender) plays a part in its creation." It'll be "transparent like a Jelly Fish to a degree" and partially based off Jon Spaihts' Ultramorph, an enormous Xenomorph that an Engineer gives birth to in an early Prometheus draft. You can check out concept art of the unused creature on the right.
Their source doesn't provide any information on the second monster, though, it would make sense for it to be the Deacon, which was the creature that emerged from the chest of the Engineer at the very end of Prometheus.
Alien: Covenant will begin filming in February for a 2017 release.