Tibia is a very dangerous place, with many different creatures living in only marginal cooperation with eachother. Sometimes creatures will execute a raid on a nearby town or city. There is usually very little warning before a raid occurs. If monsters are not killed, they will stay until next Server Save.
If you are caught in a raid, and are not prepared, or you are too low of experience level to survive, you should head to the nearest Protection Zone (Temple, Ship, House, etc.) or go up/down one level.
Potential Raids
Rat Plague in Thais
Sometimes the rat problem in the Thais sewers spills over into the streets.
There is continual unrest in the Ghostlands west of carlin. It is inevitable that this unrest and anger will sometimes spill over into the land of the living.
The sands of the Kha'labal contain many scarabs. Sometimes they will find their way to the surface and pose a great amount of danger to anyone caught in their path.
Warning
"Unusual frequent scarab sightings at the gates of Ankrahmun"
"Ancient scarabs are leading an attack on Ankrahmun."
The Apes of Banuta do not have the knowledge and ability to sustain their own existence. From time to time, they will raid the nearby human settlement of Port Hope to gather supplies.
Ever since their defeat and banishment, the Brotherhood of Bones and their Undead armies in Drefia have constantly sought vengence upon their enemies. Even though the humans are not their primary target, they will take every opportunity to attack and kill them.
Warning
"Sightings of undead, west of Darashia! Imminent invasion is suspected!"
The Grynch Clan Goblin raid is a special raid that happens on Christmas. They drop a nice amount of loot, and therefore many people look forward to this kind of raid.
It can happen on any major city.
Warning
"Goblins of the infamous Grynch Clan are invading city to steal all presents, Beware!"
"The Goblins sometimes have stolen presents with them! Confiscate them!"
"Return the stolen presents to Ruprecht on Vega at Santa's home for a reward."
Creatures from Grynch Clan Goblin Invasion on city
Dwarf Soldiers come silently to attack the inhabitants of Cormaya. Some say they want to reclaim the paradisiac island they found years ago, while traveling through an underground river deep below Tibia.
Others say this is a newly introduced anti-AFK measure from the creators of the game.
Warning
There is no warning before the Dwarf Soldiers commence their strike in the island of Cormaya.
Sometimes you might meet orcs inside and around the lighthouse south of Thais. On the ground, there are some plain vanilla orcs and one zerk. When travelling higher in the tower you will meet their stronger fellows.
"The Ruthless Seven have risen to hold their secret council. They will gather somewhere in the Plains of Havoc to debate Tibias destiny and doom. Don't come to close, for if you do, you will face your own destiny!"
"The herald of the Ruthless Seven is preparing their arrival close to the spiders rock. Behold mortals. It is the end of times!"
Creatures from April's Fool Raid in Plains of Havoc