Dark Grungs are small froglike creatures related to the more common tropical colorful Grungs, though only found in the forests of temperate and cold regions. While the tropical variant has bright colorations, the Dark Grung, as its name suggest, is similar in color to common toads, ranging from olive green to a deep forest green.
Juvenile Grungs are hunted for their weaker poisons that have euphoric effects. See Grungine for details on the drug and its production.
Exactly the same as any regular Grung (Volo's pg. 156), but when consumed (and it is young enough) it can (DC 16 Constitution) have the effects of Lesser Grungine.