Joe Orlando script credit from House of Mystery: The Bronze Age Omnibus (DC, 2019 series) #1.
Signature (Meskin) on lower edge of splash panel.
Following discussion on GCD Main, inker changed to George Roussos with a query on Meskin as inker. Meskin and Roussos had a collaborative relationship from the 1940s onwards (information from Lambiek).
While Meskin and Roussos DID collaborate extensively during this period, their inking styles were quite distinct. A look at the faces in close up will usually reveal which man has inked them. This looks like pure Meskin.
Sergio Aragonés script credit from House of Mystery: The Bronze Age Omnibus (DC, 2019 series) #1.
Sergio Aragonés script credit from House of Mystery: The Bronze Age Omnibus (DC, 2019 series) #1.
Len Wein script credit from House of Mystery: The Bronze Age Omnibus (DC, 2019 series) #1.
Letters submitted by Scott Strider; Doug Brown; Ralph Alfonso; "Countess Deborah."
Story has Swamp Thing and Parliament of Trees similarities or overtones, and is listed in Overstreet as "Swamp creature story by Wrightson similar to Swamp Thing." One creature looks like The Heap plus there is an Old Ones / Elementals ("creatures of the old hills") vibe.