Shimmer Seal

Medium beast, unaligned

Armor Class 12
Hit Points 105 (14d8 + 42)
Speed 30 ft., swim 40 ft.

18 (+4) 14 (+2) 17 (+3) 5 (-3) 12 (+1) 9 (-1)

Saving Throws Wis +4, Cha +2
Skills Acrobatics +8, Performance +5, Stealth +5
Damage Resistances cold
Senses darkvision 60 ft., passive Perception 11
Challenge 5 (1,800 XP)


  • Limited Invisibility. When the shimmer seal is on an icy surface or underwater, it is invisible. In all other terrain, the shimmer seal has advantage on Dexterity (Stealth) checks. Seals, other pinnipeds, and creatures chosen by the shimmer seal can see it.
  • Sureflippered. The shimmer seal can move across and climb icy surfaces without needing to make an ability check. Additionally, difficult terrain composed of ice or snow doesn’t cost it extra movement.
  • Underwater Propulsion. When the shimmer seal is underwater, it can take the Dash action as a bonus action on each of its turns.


  • Multiattack. The shimmer seal makes two tusk attacks.
  • Tusk. Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 14 (3d6 + 4) slashing damage.


This tusked seal is nearly transparent, including its internal organs, except for a few spots dotting its hide.

Unseen Pinnipeds. Shimmer seals traverse their typical habitats hidden from prey and predators alike. Their translucent skin and internal organs allow them to blend in with water and against icy backgrounds. Against other backgrounds, they leave a telltale shimmer, giving them their name. However, the seals can still take the unwary by surprise in less-than-ideal conditions. The only time the seal fully loses it translucency is when it consumes its diet of fish or small mammals, during which observers receive a breathtaking (or nauseating) view of the seals’ digestive process. The seals are aware of this vulnerability and usually feast in hidden locations.

Arctic druids and rangers who successfully befriend shimmer seals use them as spies or as an advance wave of attack.

Guardian of Seals. Though shimmer seals notionally look like harbor seals, they are found among many different species of seal. Scholars who have studied the strange seals concluded shimmer seals are created when the spirits of creatures passionate about protecting overhunted animals merge with those of ordinary seals.

When a shimmer seal dies protecting a pod of seals from hunters, one of the seals transforms into a new shimmer seal within a minute of the other shimmer seal’s death, reinforcing this theory. While shimmer seals are vigilant against hunting by humanoids, they allow natural predators to cull the seals under their protection, understanding the natural order and its importance.

Rallying Seal. A shimmer seal allows other seals to see it, and it can allow allied creatures to locate it. The presence of a shimmer seal emboldens the seals under its protection, transforming a pod of seals that might scatter in the face of armed opposition into an army of teeth and flippers, with the shimmer seal leading the counterattack. No one knows if the shimmer seal is aware of its ability to reincarnate shortly after it dies, but its fearlessness points to it possessing a certainty of survival.

Section 15: Copyright Notice

Tome of Beasts 2. © 2020 Open Design LLC; Authors Wolfgang Baur, Celeste Conowitch, Darrin Drader, James Introcaso, Philip Larwood, Jeff Lee, Kelly Pawlik, Brian Suskind, Mike Welham.

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