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Archelon

Huge Beast (Dinosaur) · · CR 4

  • Beast (Dinosaur)
  • Huge
  • Tier 1

CR 4 huge beast (dinosaur), unaligned — that's Archelon. Native to underwater. Sourced from Monster Manual (5.5e 2024).

Stat Block

Challenge Rating
4
Type
Beast (Dinosaur)
Size
Huge
Alignment
Speed
Habitats
Underwater
Sources
Monster Manual (5.5e 2024)

Ecology

Archelons are giant sea turtles that grow to fifteen feet across, inhabiting deep ocean trenches and ancient coastal reefs. They feed on jellyfish, kelp, and slow-moving fish, using powerful jaws to crack shellfish. Females come ashore once per decade to lay clutches of leathery eggs in volcanic sand, where heat incubates them for years. They share habitat with whales and giant squid, mostly indifferent to other megafauna unless threatened. They live for centuries.

Behaviour

Archelons are gentle but territorial, especially around nesting beaches. They patrol slowly, using powerful flippers to glide vast distances. They can hold breath for hours, but surface to bask in sunlight. When threatened, they retract into their shells and ram aggressors with armored skull-plates. They communicate via low-frequency moans, audible miles away underwater. Aged archelons are revered by aquatic druids as living memories of forgotten ages, often consulted by deep-sea sages.

Origin

Archelons are remnants of an age when the seas teemed with giant reptiles. Their ancestors swam among plesiosaurs and mosasaurs in primordial oceans. Some lineages persist in ancient feywild seas or are cultivated by aquatic druids who consider them sacred. Tritons and merfolk often see archelons as living temples, riding their backs during religious processions. Their fossil shells are prized by surface-dwellers as proof of vanished worlds.

CR 4 monstersAll Beast (Dinosaur)sUnderwater

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Frequently Asked Questions about Archelon

What is the challenge rating of Archelon?
Archelon's challenge rating is 4. A party in this band matches tier-1 encounter math.
What type of creature is Archelon?
Archelon is classified as a beast (dinosaur) in D&D 5e, huge size.
Where does Archelon live?
Archelon is at home in Underwater.
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QR code linking to Archelon — https://www.doungim.com/dnd/monsters/archelon Scannable QR code encoding the URL https://www.doungim.com/dnd/monsters/archelon. Point a phone camera at this code to open the Archelon page on your mobile device — useful at the table when a DM's laptop or a printed sheet is showing the page.
Scannable QR code encoding the URL https://www.doungim.com/dnd/monsters/archelon. Point a phone camera at this code to open the Archelon page on your mobile device — useful at the table when a DM's laptop or a printed sheet is showing the page.