Guess which one this is.
I'm quite pleased by the simplicity of the monster stat blocks. They have been kept neat, tidy, and give the info needed in an easy to read format, which is great when running a combat. The format reminds me of the 4e stat blocks which is one thing I did like about that edition.
Go take a peek at the info over at EN World.
The three creatures revealed are all Challenge 2 and 450xp. I am still baffled by what the 5e challenge ratings represent, though it won't be long before we all find out. Basic D&D will be free to download as soon as July 3rd. (just character creation, the other bits will be added as books are released)
Getting back to the Nothic . . . The flavor text in the description states that they were once wizards that "unlocked magical knowledge they could not fathom". They also can learn knowledge from people they directly observe, even hidden knowledge. They also possess True Sight, so no fooling them with invisibility or illusions. Nothics are also above average intelligence, they easily could use their wits to smartly stalk and study intruders. I can really picture a Lich having a couple of these as "eyes" within or near the lair.
EDIT: I noticed something about all three of these monsters. Their to-hit in combat is equal to 1st level characters. The Ogre has +6 which is derived from its strength modifier of +4 and the proficiency modifier of +2. Both the Nothic and Ochre Jelly have strength modifiers of +2 and proficiency of +2 for +4 to hit.