They're also solid, so you're forced to go around them else you'll get stuck on them. Since you're basically worried more about what's chasing you, the appearance of this Specimen will probably catch you unguard many times, and the fact that your character in-game freezes when that happens may make you really vulnerable to any Specimen that may be close to you.
Why? Because it can also appear when you're being chased by another Specimen. However, while it can't hurt you, it's possibly one of the most annoying Specimen that will appear. This causes a high sound effect to appear and your character freezes for one second, representing the fact the character you're playing as was startled with its sudden apparition (and probably you'll be startled too sometimes). They suddenly appear out of nowhere, specially if you're holding the Run button. There's different types, but I'll only show you one here. The first Specimen you'll find, it's basically a cardboard drawing of a cute or not cute monster.
