Two foot high ratlings, humanoid, dressed in simple leather and cloth garments and carrying needle knives (sometimes poisoned) and tiny bows and slings. They are primitive by some measures, but civilised, living (typically) in large nest communities. Teams of TU-Rats have been known to ride pack-horses and other large domesticated animals. Unlike other rats and ratlings they have long outgrown scavenging as a way of life.
Oh, and TU stands for Telepathically United.
The cranium of a TU-Rat is slightly larger than might be expected for a bipedal rat of their overall size. They create an open psychic field to other TU-Rats. They are individuals but share and coordinate via a groupthink as situations require. A TU-Rat is always aware of every other TU-Rat within 50 feet, and can transmit to TU-Rats much further away by a mental relay effect: messages are passed on but are not instantaneous.
TU-Rats trade with other intelligent races sometimes. They are not aggressive generally, but can be territorial. A TU-Rat by itself will not be a great challenge for a party of adventurers if they have to kill it. Problems occur when dealing with large groups of TU-Rats that attack en masse and which can overcome even the most hardy of warriors. The TU-Rat psychic field can have an effect on humans and other races.
AC: Leather +shield; 1HD, 2+d6HP
Attacks: Any TU-Rat encountered outside a nest will have a 75% chance of carrying one or more needle-knives (d4 damage) which have a 10% chance of being poisoned (see table for poison effects). TU-Rats in army or battle groups will have poisoned knives 30% of the times. TU-Rats have a 25% chance of being armed with a miniature short bow (d4 damage). They can also bite (d2+poison, see below).
Special: TU-Rats gain attack bonuses by the cube root of the number in a group (rounded down). So for 1-7 rats they would each get an attack bonus of +1; 8-26, attack bonus of +2; 27-63 a bonus of +3; 64-124, each gets +4 and so on. This should realistically top out at around +7 or +8 depending on group formations.
A TU-Rat can call any other TU-Rat within 50 feet, who will come (on two legs) as quickly as the situation demands. TU-Rats have no spoken language. When communicating with outsiders they use picture books and hand gestures to get their message across.
A dying TU-Rat will send a psychic death-squeal that will be heard by any TU-Rat within 50+d50 feet. There is only a 20% chance of this happening if the TU-Rat is sneak-attacked (and killed in that one blow).
TU-Rats in large groups have been known to (inadvertently) cause headaches in Magic-Users and the particularly intelligent. A Magic-User or anyone with an INT score over 10 must roll over their INT score or take an ongoing -2 penalty for attacks and any action requiring concentration for d6 hours.
Groups encountered in the wild: Roll d6
1. 3d4 TU-Rats, a small group.
2-3. 10+4d6 TU-Rats, probably armed, possibly not hostile.
4. 20+3d20 TU-Rats, small skirmish or hunting group.
5. 100+5d100 TU-Rats, battle group.
6. d2 * 1000 +d1000 TU-Rats, a whole army, war party, kingdom on the move. (DAMN.)
TU-Rats create large nests under hills, in abandoned towns and castles, and in some cases in their own built towns and villages. An "average" nest, whatever the appearance, will have approximately 700-800 individuals in it.
The Western Rattermund, cared for by the Dynasty of Broodmothers, comprises approximately 50,000 individuals living in and around a hollowed out and fortified hill, with a network of farms and hamlets creating a small linked empire for several miles around.
TU-Rats have a bite which delivers a bacterial disease to most humanoids. Anyone taking a bite from a TU-Rat must make a CON check or suffer a vomiting condition which manifests 2d12 hours after the bite and lasts 2d4 days. A successful CON check when symptoms appear will halve the sickness time.
TU-Rats sometimes poison their needle-knives. If a rat has laced their knife with poison roll a d6 to see type.
1. As rat-bite.
2. Save vs poison, or sleep for d3 hours.
3. Save vs poison, or paralysed for d2 hours.
4. Save vs poison, or tremors and seizures (impossible to fight, very slow in travel) for 3d10 minutes, lose 1 CON for 3 days.
5. Save vs poison, or anticoagulant: further wounds do extra 1HP damage.
6. Save vs poison, or mind opened to rat minds for 4d12 hours. INT check immediately and every six hours afterwards around TU-Rats; failure and fall into coma for d12 hours. Awaking from coma will negate access to psychic field.
Wants and Needs:
The motivations of TU-Rats are difficult to fathom for most races. They do collect valuables, and in their prior nomadic lives have found things which others might find interesting. They may or may not trade or give them to those who ask, depending on the mood of the group.
An isolated TU-Rat will be confused and scared at first, and then anxious to make contact with a larger group.
TU-Rats have been known to war amongst each other and against aggressive humanoids. It is rare for them to go to war without provocation.