The Warped Beholder on page 14 has a couple of issues.
- First, it looks like the name of the monster was changed late in the process. In the first line, it's called Warped Beholder, but everywhere else in the rules text, it's Omaranthax. If it's put into the Compendium, then all references to Omaranthax should be changed to Warped Beholder.
- Second, this creature has the blind keyword along with darkvision. I think it had blindsight at some point and had it changed, or that it was a copy/paste error from the gas spores. The blind keyword should be removed.
- Third, it's not clear whether the Random Eyestalk attack provokes opportunity attacks or not. The "does not provoke" language in Eyestalk Attack is a part of the same section which says that the Warped Beholder makes two attacks. It's also a bit confusing that Random Eyestalk is a ranged attack, but four of the ten Eyestalk Attack choices aren't ranged attacks.
The Farspawn Wretches (p. 7, 12, and 14) have Screaming Echo as an immediate interrupt when killed. If it's an interrupt, it happens before they die, so the wretch still occupies the square. It should be "No Action" because the trigger is being reduced to 0 hit points.