Stirge

Stirges are weird winged creatures that some say may have invaded from some other plane of existence. They are relatively small, just about 1 foot long with a wingspan of about 2 feet and an average weight of 1 pound. They vaguely resemble hairless bats with a rubbery tubular proboscis and no back legs (so that their body simply comes to a blunt point at the rear). If a stirge hits a living creature, it grabs on with hooked claws on its wing joints and quickly embeds its proboscis in the victim's body. The proboscis has rows of tiny serrated teeth on the inside, and literally turns itself inside out as it carves a way into the victim's body. This causes 1d4 points of damage, and the stirge then proceeds to suck the victim's blood, inflicting an additional 1d4 points of damage each round. Once attached, the creature can only be removed by killing it. The victim cannot use weapons larger than a dagger or hand axe to attack the creature, and cannot attack it at all if attacked from behind. Others may attack the creature with a bonus of +2 on the die roll, but any attack that misses hits the victim instead.