The Acid Frog From the sourcebook No Humans Allowed

Genotype:

The acid frog was developed on Venus by Micro-Surgery, Inc. of Aphrodite to provide a natural enemy for swamp hornets, also created by MSI. Swamp hornets fill a scavenger role in the new Venusian ecosystem, but the nasty insects nearly overran the early Venusian colonists before they determined that a predator needed to be introduced into the system for balance.

Acid frogs are based on the gene pattern of a South American tree frog, with greatly enhanced size and a tolerance for the highly acidic environment of the Venusian lowlands. Not wishing to repeat the mistake they made with the swamp hornet, the genetic engineers in charge of the acid frog genotype project also gave the gennies a very docile demeanor. In fact, Venusians who have treated the acid frogs with kindness (freeing them from captivity, feeding them, protecting them from danger, etc.) have had the animals follow them around, behaving almost like pets, to the point of even attacking their enemies!

Physical/Cultural:

Physical size: 8 to 10 feet long, 4 feet high, 400 lbs.
External covering: Acid-resistant amphibian skin
Eyes: Amphibian normal
Ears: Amphibian normal
Mouth: Amphibian normal with speech articulators allowing it to speak a crude form for English
Nose: Amphibian normal
Cultural: Acid frogs live in large groups near their favourite food, swamp hornets. Where the hornets go, the frogs will follow.

Acid frogs are immune to the effects of gas grenades and take only one-half damage from heat guns and plasma throwers.

Combat:

Acid frogs are docile creatures, but when forced into combat situations, they have two types of attacks. One is a bite causing 1d10 points of damage; the other is a stream of acid which can be spit with amazing accuracy. The acid stream also does 1d10 points of damage, but the victim gains a saving throw versus Toxic Atmosphere/Gas/Poison for one-half damage. There is a 50% chance the acid frog will spit instead of bite, rolled randomly by the referee each round. Acid frogs have an unlimited supply of acid, and the stream has a range of 60 feet.

Habitat/Terrain:

Acid frogs thrive in the acidic swamps of the Venusian lowlands, though they can travel to other parts of the lowlands as well. The frogs can survive nearly a week (1d6 days) without immersing themselves in the acidic waters of the swamps, but they do not like it. After a day or so of hunting and foraging for swamp hornets, they head back to the swamps they call home.

Ecology:

Acid frogs are not picky eaters. When swamp hornets are scarce, they eat plants, other insects, small animals, and even the occasional adventurer or two. (Acid frogs will never eat the humans they befriended.) Acid frogs rarely attack unless provoked, but a hungry one is likely to go after anything that moves which it can fit into its mouth.

Acid frogs have developed a loose society, though what it is based on is anyone's guess. The only thing outside observers know for sure is one acid frog out of 40 or 50 makes suggestions the other follow. Acid frogs are not too bright, but they are smart enough to speak a crude form of English and to communicate with other intelligent species. Their speech is slurred and very guttural. Intelligence equal to or greater than the Terran average (Intelligence 8) is required to understand their vague vocalizations.

Saving Throw Modifiers:

Explosion/Plasma	+2	Electrical Shock	+1
Paralysis/Stun/Fall	-2	Toxic/Gas/Poison	+3
Suffocation	-4	Radiation	+1
Extreme Heat	+2	Extreme Cold	-5

The acid frog originally appeared in the XXVc comic module BUCK ROGERS #6