[s1e9] The Anatomy Lesson -

Watch a deep-dive discussion and review of this pivotal episode here:

To confirm this, Swamp Thing later retrieves Alec Holland’s actual decayed corpse from the water, realizing he is merely a plant mimicry. Subplots & Transformations [S1E9] The Anatomy Lesson

He is a mass of swamp vegetation that "dreamed" it was Alec after absorbing the scientist's memories and DNA following the lab explosion. Watch a deep-dive discussion and review of this

The episode is noted for its "noirish" aesthetic and gruesome special effects during the autopsy scene. [S1E9] The Anatomy Lesson