A sourced illustration has not yet been added. This gap is included in the coverage record.

Overview

The legacy hydra has a crocodilian body and several long necks, usually bearing five heads. It can swim and hold its breath for an hour, placing the published monster comfortably in swamp encounters. Multiple heads are mechanically important rather than merely decorative: they support additional opportunity-attack reactions and a bite for each remaining head. The 2014 creature also benefits from its divided awareness against several disabling effects, and one head stays awake while the others sleep. Substantial damage within a single turn removes a head; losing every head kills the creature. Removing one or two heads carelessly can instead worsen the encounter.

Both selected editions allow two replacements for each head lost, with fire preventing that regrowth. Their healing differs: the legacy rule restores health for each regrown head, whereas the revised rule gives a fixed amount when new heads grow. The newer creature also swims and moves faster, and its listed condition immunities replace the legacy advantage that depended on having more than one head. Its published block does not retain the separate Wakeful trait. These differences matter when adapting an older encounter rather than assuming identical resistance and recovery in both books. The revised habitat list includes coasts as well as swamps. This is head regeneration within one surviving animal, distinct from Warcraft hydras whose defeated units can divide into smaller whole creatures.

Multiple biting headsFire prevents head regrowthAquatic movement
01

First appearances & development

The selected witnesses are Monster Manual (2014) and the revised Monster Manual (2025), rather than a claim to survey every earlier D&D hydra. The creature’s recognizable multiple-head and fire-countered regeneration pattern adapts a familiar mythic motif, but this profile does not assign a specific designer’s historical inspiration without separate testimony.

02

Canon & continuity

Individual publisher records were read for anatomy, swimming, breath holding, head loss, replacement, healing and reactive attacks. Their different condition defenses and the presence or absence of Wakeful are explicitly scoped. The Warcraft comparison refers to this compendium’s separately sourced Warcraft entry, rather than claiming that one franchise supplied the other.

Selected bibliography

Documented works and useful reading. This is not a list of every appearance.

  1. 01

    Monster Manual (2014)

    Wizards of the Coast · 2014

    Legacy divided awareness, Wakeful and healing per replacement head.

  2. 02

    Monster Manual (2025)

    Wizards of the Coast · 2025

    Revised condition immunities, movement and fixed regrowth healing.

Family & connections

A source-supported family tree or inspiration record has not yet been compiled for this profile. Related reading below indicates a connection in subject matter, not a proven lineage or creative influence.

References

Sources supporting this profile. Linked pages have their own scope and editorial standards.

  1. OfficialHydra — legacy monster recordResearch access: 2026-10-05
  2. OfficialHydra — revised monster recordResearch access: 2026-10-05

Image credits

A sourced illustration has not yet been added. This gap is included in the coverage record.

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