Horsefly, Giant

Horsefly, Giant

This creature looks like a common, hairy, black and green horsefly, except it is 8 feet long.

Giant Horsefly

XP 100 ()

Unaligned Large

Initiative +2


AC 12

hp: 30 (4d10 + 8)


Speed: 20 ft., fly 60 ft.

Melee Attack—Bite: +4 to hit (reach 5 ft.; one creature). Hit: 1d8 + 2 piercing damage and the target is grappled.

Melee Attack—Fluid Drain: automatic hit (one creature already grappled by the Giant horsefly at the start of the horsefly’s turn). Hit: 1d6 + 2 piercing damage and the target must make a successful DC 12 Con saving throw or become paralyzed until it is no longer grappled by the Giant horsefly.


Str 15 (+2), Dex 15 (+2), Con 14 (+2),

Int 1 (–5), Wis 12 (+1), Cha 7 (–2)

Languages: None

Senses: Tremorsense 60 ft.



Organization: Solitary, pair, or nest (10–20)

Giant horseflies are aggressive relatives of the smaller, common horsefly, and they generally frequent the same types of habitats. Their lairs are always dug near water, where the lair will stay damp from water in the surrounding ground. A typical nest contains one female and up to 20 males.

During warmer months but especially when the temperature is high, a flurry of activity can be noticed around the nest. This is the horseflies preparing for the colder months and for the time when the female lays her eggs. One male is taken as a mate, and during the spring or fall months, the female lays a clutch of five to eight eggs. Larvae hatch within a few weeks and resemble Giant grubs with segmented bodies. Each segment of the larvae’s body has short protuberances that are used like stiff, unjointed legs to aid in movement.

Giant horseflies sustain themselves on a diet of nectar, pollen, blood, and other bodily fluids. Their hunting territory covers a range of several square miles around their nest. Any and all animals are targeted for their blood, from wild creatures to domesticated livestock to unlucky humanoids.

Except for their size, Giant horseflies look like large, black, hairy flies. Their bodies are thick and their multifaceted eyes reflect many dark colors. Their wings are translucent and their legs are long and bristly. Females have a slightly longer mouth tube than males.

Giant horseflies attack by delivering a painful “bite” to their opponent that amounts to gripping it with their forelegs and stabbing it with their needlelike proboscis. The fact that an area is inside a nest of Giant horseflies’ hunting territory can sometimes be recognized by the bodies of animals and people that have been drained of fluid and left to rot on the ground; Giant horseflies siphon out their victims’ body fluids but do not eat any other part of them.