Green Slaad

(from Planescape Monstrous Compendium Appendix I - 1994):

Whether as a host for a reds egg-pellet or as a blue’s disease victim, a powerful human or demihuman host (such as a high-level adventurer) sometimes spawns a baby green slaad instead of a red or blue. This is an auspicious occasion, and both red and blue slaadi nurture the young green carefully. At maturity (10-12 years), green slaadi have somewhat higher foreheads than reds or blues, typically with several tattoos. In their century-long careers they acquire many forehead tattoos.

Green slaadi are defensive about weaknesses and self-aggrandizing in triumph. Tremendous braggarts, they sometimes pause even during combat to gloat over opponents.

Combat: Green slaadi attack with two claws (1d6+2 damage) and bite (2d8 damage). They prefer to use their innate powers or gate in other slaadi for combat, but they fight viciously if pressed. A green slaad can polymorph at will into a duplicate of the human or demihuman host that spawned it.

Green slaadi as a group have demonstrated the following spell-like powers, usable one at a time, one per round, at will: darkness, 15’ radius, delayed blast fireball (once per day), detect invisibility, detect magic, ESP, fear, locate object, produce flame, and telekinesis. No individual green slaad has shown all of these powers.

Twice a day, with a 50% chance of success, they can attempt to gate in 1-6 red slaadi, 1-4 blue slaadi, 1-2 green slaadi, or 1 gray slaad. Green slaadi are harmed only by +1 or better weapons.

(from D&D 3rd Edition Monster Manual - 2000):

This tall, gangly creature looks like a cross between an ogre and a frog. Its skin is a mottled green, and it has long, sharp claws and a wide mouth. 

If a red slaad’s egg pellet or a blue slaad’s disease infects an arcane spellcaster, that host produces a green slaad. A green slaad is about 10 feet tall and very broad. It weighs about 1,000 pounds. As its name suggests, a green slaad is mostly green, darker along the back and paler around the belly. 

Green slaadi are self-centered, arrogant louts that think only of themselves. They lust after magical power, eventually transforming into grays (see below) if they find it. 

Green slaadi work in groups if doing so suits their immediate needs.

Combat: Green slaadi prefer to use spell-like abilities over physical combat but aren’t afraid to attack with tooth and claw if they must. They never fight to the death, though, if they can avoid it. 

Spell-Like Abilities: At will— chaos hammer (DC 15), detect magic, detect thoughts (DC 13), fear (DC 15), protection from law, see invisibility, shatter (DC 13); 3/day— dispel law (DC 16), deeper darkness, fireball (DC 14). Caster level 9th. The save DCs are Charisma-based. 

Change Shape (Su): A green can assume any Medium or Large humanoid form as a standard action. In humanoid form, a green slaad cannot use its natural weapons (although a slaad can equip itself with weapons and armor appropriate to its appearance). A green slaad remains in one form until it chooses to assume a new one. A change in form cannot be dispelled, but the slaad reverts to its natural form when killed. A true seeing spell reveals its natural form. 

Summon Slaad (Sp): Twice per day a green slaad can attempt to summon another green slaad with a 40% chance of success. This ability is the equivalent of a 5th-level spell.

(from D&D 5th Edition Monster Manual - 2014):

Green slaadi are surprisingly intelligent and possess innate spellcasting ability. A green slaad can change its shape to appear as a humanoid. If it was born of a humanoid host, the slaad usually adopts its host’s form.

At some unpredictable point in its existence, a green slaad unlocks the means to magically, instantly, and permanently transform itself into a gray slaad. Unlocking this knowledge can take years, even decades.