Plesiosaurus
Large Beast · · CR 2
- Beast
- Large
- Tier 1
Ranges across coastal, underwater, and arctic; Plesiosaurus lists at CR 2 as a large beast (unaligned). Sourced from Monster Manual (5e 2014) and Monster Manual (5.5e 2024).
Stat Block
- Challenge Rating
- 2
- Type
- Beast
- Size
- Large
- Alignment
- —
- Speed
- —
- Habitats
- Coastal, Underwater, Arctic
- Sources
- Monster Manual (5e 2014), Monster Manual (5.5e 2024)
Ecology
The plesiosaurus is a long-necked marine reptile surviving in deep coastal waters, arctic seas, and isolated lakes. It feeds on fish, squid, and seabirds, using its long neck to strike from below or amid kelp. Females lay leathery eggs on remote shorelines, returning to sea for years before another clutch. The species is solitary; multiples in one bay indicate abundant food or a lost school of prey.
Behaviour
Curious rather than aggressive, the plesiosaurus investigates floating objects and may bump small boats playfully. Hunger or territorial defense changes this: a hungry plesiosaurus capsizes vessels and snatches swimmers. It dives to deep cold water to escape threat, holding its breath up to an hour. Mating displays involve neck-arching in shallows, often misinterpreted as attack by surprised sailors.
Origin
Lost-world settings preserve plesiosaurs in pocket prehistoric ecosystems: hidden valleys, polar continental shelves, and bottomless lakes. Some are awakened by shifts in planar boundaries, surfacing through dimensional rifts. In divine cosmologies, a primordial sea-creator once shaped them as her children before retreating. Sailors invoke their patron sea-deity to ward off encounters with the long-necked shadow.
Related Monsters
Frequently Asked Questions about Plesiosaurus
- What is the challenge rating of Plesiosaurus?
- On the bestiary CR scale, Plesiosaurus sits at 2. It works against tier-1 parties.
- What type of creature is Plesiosaurus?
- Plesiosaurus is classified as a beast in D&D 5e, large size.
- Where does Plesiosaurus live?
- In the bestiary, Plesiosaurus appears in Coastal, Underwater, Arctic.