Life-Cycle
Gricks begin life as buds growing on the backs of their parents. After two weeks of a process akin to gestation, however, they fall from their parent's bodies and are abandoned. Within a few hours they become mobile, resembling like pale green lozenges with bristles growing from one end. They are only capable of very limited movement, however, and are completely unable to defend themselves. Few gricks survive this stage, as the larvae are often eaten by scavengers or trodden on by larger monsters who fail to notice them. If they survive this, they begin eating as soon as possible, surviving on waste matter and carrion if they can find it.
If they do not starve to death and avoid being eaten by predators, the larvae grow to resemble slugs. They move about on a muscular appendage called the radula, and leave a slippery trail of mucus in their wake. They are still unable to hunt their prey but have a greater scavenging instinct.
As the larvae continue to develop, their radula divides into two halves, which in turn divide into the tentacles that characterise the fully-grown grick. By this time they have learned to slither faster, their musculature has developed to such an extent that the gricks can rear up easily, while their beaks has hardened into vicious weapons, capable of tearing chunks of meat from a carcass. They have not forgotten the lessons taught them in their youth, and despite their new predatory capability they still prefer a stealthy assault to simply charging to the attack.
Grick larvae take roughly three months to reach maturity, continually eating and growing. Once they have reached full size, they are able to reproduce. Gricks continue growing beyond adulthood, rivalling ogres in bulk and weight. While they are less stealthy than their younger and smaller kin, they compensate by being fiercer and more aggressive combatants. Fortunately, this process does not continue for long; they tend to live no longer than twenty years before expiring.
Mindset
Since gricks are only semi-intelligent, there is little to say about their thought processes. Attempting to communicate with them is pointless, as their small brains are incapable of handling or conveying complex concepts. However, there is evidence that their tiny minds are quite alien to humanoid races, given that their minds are difficult to control. Like the vast majority of aberrations, their Will saves are their strongest.
Gricks have simple needs and accordingly primitive minds. They do not concern themselves with such ideas as morality or emotions, because quite simply they have no need for that sort of confusion. However, there is a certain level of cunning about them that could give actual problem-solving intelligence a run for its money. If its prey is too large to drag back to its lair, the grick will simply attempt to rip the carcass into suitably large pieces. If the way toward more food is obstructed, the grick will seek alternative ways in. In terms of intelligence, many monsters are smarter than gricks, but the majority of animals are perhaps less clever, and to dismiss them as being as stupid as vermin can be a fatal mistake.
Habitat
Gricks are primarily subterranean monsters. They are usually found in natural caverns or the tunnels left by burrowing creatures such as purple worms or ankhegs, but more recently they have started cropping up in man-made structures including tombs, cellars and mines. They can be found at all levels of a subterranean region, but will generally be found close to areas where food is plentiful. They are not bothered by the weather on the surface, and will venture out during any season, but will always do so at night-time. While they adapt quickly to many situations, they avoid sunlight whenever possible.
The Depths
Most gricks prefer to stay in the bowels of the earth, preferring the dark and the damp. Unlike the sentient race never venturing out in broad daylight.
Their nests are usually located in places of comforting darkness situated near towns and villages. These lairs are never more than half a mile from their preferred hunting grounds. Gricks who settle near farming communities are especially loathed as they tend to pick on livestock first, dragging sheep away or ganging up on cattle. A fully-grown ram is a sufficient day's meal for an entire cluster of gricks, although a single grick will quite happily attempt to take its prey on single-handed, leaving a mutilated carcass behind once it has gorged itself.
Gricks that settle near urban areas are feared more, however, as the only readily available prey are humans and their kind, and in areas of high grick infestation there are always several disappearances as young humans and halflings are easily carried away to be devoured at leisure.
Water and Sustenance
While most forms of life require water in order to survive, gricks do not need to find a source of pure water. They are quite capable of meeting all these requirements through two means; firstly, their hides are capable of a form of osmosis, extracting water vapour from the air. The rest of their moisture requirements are met by extracting water from their prey. It is because of this rather ghoulish practice that corpses that have been butchered by gricks always appear desiccated and dried out.