Huge monstrosity, neutral

Armor Class 16 (natural armor)
Hit Points 216 (16d12 + 112)
Speed 30 ft., swim 90 ft.

20 (+5) 10 (+0) 24 (+7) 7 (–2) 12 (+1) 15 (+2)

Saving Throws Dex +4, Int +2, Cha +6
Skills Perception +5
Damage Immunities cold Senses passive Perception 15
Languages understands Common but can’t speak
Challenge 11 (7,200 XP)
Proficiency Bonus +4


  • Essential Oiliness. The imperator has advantage on saving throws and ability checks made to escape a grapple or end the restrained condition.
  • Hold Breath. The imperator can hold its breath for 1 hour.
  • Penguin Telepathy. The imperator can magically command any penguin within 120 feet of it, using a limited telepathy.
  • Siege Monster. The imperator deals double damage to objects and structures.


  • Multiattack. The imperator makes one Beak attack and two Wing Slap attacks.
  • Beak. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 24 (3d12 + 5) piercing damage. If the target is a Large or smaller creature, it must succeed on a DC 17 Dexterity saving throw or be swallowed by the imperator. A swallowed creature is blinded and restrained, it has total cover against attacks and other effects outside the imperator, and it takes 21 (6d6) acid damage at the start of each of the imperator’s turns. If the imperator takes 30 damage or more on a single turn from a creature inside it, the imperator must succeed on a DC 17 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall prone in a space within 10 feet of the imperator. If the imperator dies, a swallowed creature is no longer restrained by it and can escape from the corpse by using 15 feet of movement, exiting prone.
  • Wing Slap. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 16 (2d10 + 5) bludgeoning damage.
  • Pelagic Bile (Recharge 6). The imperator regurgitates its stomach contents in a 60-foot cone. Each creature in that area must make a DC 17 Dexterity saving throw. On a failure, a creature takes 17 (5d6) acid damage and 17 (5d6) poison damage and is poisoned for 1 minute. On a success, a creature takes half the damage and isn’t poisoned. A poisoned creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. Swallowed creatures are then regurgitated, falling prone in a space within 10 feet of the imperator.
  • Toboggan Charge (Recharge 5–6). The imperator moves up to 30 feet in a straight line over ice or snow and can move through the space of any Large or smaller creature. The first time it enters a creature’s space during this move, that creature must make a DC 17 Strength saving throw. On a failure, a creature takes 36 (8d8) bludgeoning damage and is forced prone. On a success, a creature takes half the damage and isn’t forced prone.


  • Muster the Legions (1/Day). When the imperator is reduced to half its hp or lower, it magically calls 1d4 swarms of penguins. The penguins arrive on initiative count 20 of the next round, acting as allies of the vampire and obeying its telepathic commands. The penguins remain for 1 hour, until the imperator dies, or until the imperator dismisses them as a bonus action.


The massive penguin with black, gold, and white feathers tilts back its head and swallows a slain walrus. The imperator ressembles a standard emperor penguin, though built on a massive scale. It is not only bigger, but also much more intelligent and much more aggressive than its smaller kin. Thankfully, imperators are quite rare. Inhabiting desolate, ice-bound coastal regions, these massive, migratory birds travel hundreds of miles between feeding grounds and attack small boats, whales, and even the livestock of coastal villages while traveling.

Psychic Rapport. Imperators possess an intellect that surpasses the average animal. While their intelligence doesn’t rival most humanoids, they have both a deep cunning and a measure of psychic ability. Imperators can communicate with local penguin populations and even control the penguins’ behavior. In some instances, they forge local populations into a single vast colony, which they use as a personal army to attack and drive off predators and other interlopers. In times of extreme need, they devour smaller penguins as an emergency food source.

Disastrous Omen. Some coastal humanoids treat an imperator as a minor god or nature spirit, considering its appearance an omen and offering sacrifices in hopes of good fortune. However, most humanoids dread any sign of them, because their ravenous appetites can spell disaster for other creatures. A single imperator can devastate local populations of seals, walrus, and fish in a few weeks before moving on.

Imperators with colonies of penguins following them can leave famine in their wake, because the sea is cleared of most fish stocks.

Heroic Prey. Where imperators reside, there is often no greater measure of a hunter or hero than to slay such a beast. Given the havoc they can wreak on food supplies, anyone who can claim to have slain an imperator is looked on most favorably by those who have suffered their visitations before.

Loyal Legions. Colonies of emperor penguins sometimes fall under the sway of the imperator. Penguins that remain under the influence of an imperator for more than one season change, both physically and in temperament. They become larger, smarter, and more aggressive. From a distance, they look like normal, if overlarge, penguins, and their rookeries are strangely orderly, with nests equally spaced in neat rows. However, they attack in force and with surprising ferocity against trespassers, and doubly so when led by their imperator leader. When compelled by an imperator, a swarm of penguins fights without fear and to the death.

Apex Predators of Ice and Sea. A swarm of penguins, like its imperator leader, will not abide any competitors for its sources of food. The swarm attacks any perceived threats, even creatures for which penguins are normally prey, such as seals, sharks, and even whales. On land, the swarm approaches in military-like ranks, emitting low growls. When the penguins close on opponents, they fall on their bellies and slide forward in an onrushing wave of squawking, crushing bodies.

Section 15: Copyright Notice

Tome of Beasts 3 © 2022 Open Design LLC; Authors: Eytan Bernstein, Celeste Conowitch, Benjamin L. Eastman, Robert Fairbanks, Scott Gable, Basheer Ghouse, Richard Green, Jeremy Hochhalter, Jeff Lee, Christopher Lockey, Sarah Madsen, Ben Mcfarland, Jonathan Miley, Kelly Pawlik, Sebastian Rombach, Chelsea Steverson, Brian Suskind, Mike Welham

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