Beholders are slimy monsters with several tentacles that live deep in the dungeons of Tibia. They attack at sight and use their magic powers to shoot missiles. Moreover, they summon skeletons which try to surround the victim. They can sense invisible adventures. You should try to kill the beholder first and then concentrate on the remaining skeletons. Magicians can use firebombs to hurt several opponents at once.
Two adventurers battling the beholders in the dark forgotten ruins under the city of Thais
Excerpt from the book "Beholders In The Mist"
By Rune the Fox
Little is known about this species
of “monster”, the beholders as we call them have been known in the past
as fiercely territorial creatures, with mysterious roots and an even
more mysterious existence. However before passing judgement on these
strange creatures, it’s worth bearing in mind some facts about them.
Such as their dislike for other creatures, apart from undead ones that
is, as there appears to be a symbiotic relationship between beholders
and the various undead monsters of tibia, to the extent that beholders
can even control lower levels of undead (skeletons). They are prolific
diggers, and although they appear to have no appendages capable of
using tools or digging, they are responsible for a huge amount of the
tunnels in our fair land. Experts believe they command skeletons to
dig, but another plausible explanation comes from their keen
telekinetic ability, enabling them to keep themselves floating and the
dead walking, maybe even enough to part the tunnels. It is clear from
the number of eyes and the locations they are found in that they are a
quite nocturnal species as normal sunlight would hurt such large eyes.
But what proof is there of intelligence, well their minds are infact
more advanced than humans, as explained by a friendly Beholder named
486486 (or Blinky to his friends), they not only comprehend all the
other species languages, but they have their own highly advanced
language in the form of a series of blinks from its 6 eyes (so
technically a sign language, although they can communicate verbally),
their language is called 469. There have even been tales of beholders
taking in lost/abandoned humans as their own; so it’s possible they can
sense thoughts and emotions too, bear that in mind when you next
encounter this enchanting species."