Toxic- Most of the frogs, like the poison dart frog, have toxins within them.

Poisonous-: It just means the toxin is contained in the skins or tissues of these frogs.

Venomous-: Though less common in frogs, even they are found to have the ability of injecting venom.

Lethal-: Some frogs have toxins capable of killing people.

Aposematic-: Bright coloration of the frog is actually for the purpose of warning other predators.

Neurotoxin-: Affecting the nervous system, a certain kind of toxin.

Alkaloid-: The toxic compounds available in their skin.

amphibian-: Frogs belong to this class. It means cold-blooded vertebrates.

Secretion-: Dangerous frogs bear glands on the skin that secret toxins.

Endemic -: Some dangerous species of frogs are endemic to certain areas.

These words describe some of the characteristics and, to an extent, dangers involved with some species of frogs.