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Lurker

Dangerous creatures resembling manta rays that wait in high places to drop on prey

Stat Blocks

OSRIC
Armor Class6
Hit Dice10
Number Encountered1
Attacks1
Damage1d6
Move10-ft; 90-ft flying (AA:I)
AlignmentNeutral
IntelligenceNon-
XP7/1,500+4/hp
Treasure Type1d10×1,000 cp (25%), 1d8×1,000 sp (25%), 1d6×1,000 gp (25%), 1d6 gems (25%), 1d3 jewellery (25%) and any two magic items (10%)
SizeLarge
FrequencyRare
Lair95%

Monster statistics extracted from online SRD wiki, not the published hardcover edition.

Lurkers are dangerous creatures that wait in high places for prey to pass beneath them; in shape they are said to resemble manta rays, but have such colouration and form that they can become almost indistinguishable from the stone of the caverns in which they dwell.