Aluterus monoceros, or the unicorn leatherjacket, is a marine fish with a long protrusion on its head. It lives in warm oceans and feeds on algae and small animals.
The unicorn leather fish stands out with a long horn on its head and rough skin. It helps maintain reef balance by eating algae and serves as food for large predatory fish.
Immature form that undergoes metamorphosis before adulthood.
Worker
scraping
birth time
Pelagic Ocean
Dogs, dolphins, lynx hang out for 9-25 years and party on their birthday three times a year
m
Map
will celebrate their {n} birthday
g
t
When your next jubilee falls in {name} life years
Human
hot Africa south of the desert, many savannas and forests
days
marine pelagic
coral and rocky reef
How old you would be if you lived as {name}
jellyfish
Theoretical maximum lifespan estimated from the Dynamic Energy Budget (DEB) mathematical model. This value reflects a biological potential derived from metabolic parameters, not from direct observation — real recorded lifespans are often significantly shorter.
Rasping or abrading food surfaces with teeth or mouthparts.
adult
Maturity
sea urchins and stars
South and Central America, hot and humid, huge forests
invertebrates
Melon
About health
marine coastal
When your next birthday would fall if you lived as {name}
results
Southeast Asia and islands, always hot and humid
Colors
Caudal fin color
Sex
Upcoming jubilees
Gremllins
mo
all seas and oceans
Trophic type
all living animals without backbone
Filters
Captures or processes food by biting or nipping with the mouth.
Upcoming birthdays
live jellyfish
Truly long lives: 40-100 years. Bowhead whales, albatrosses, giant tortoises recall their birthday at most once a year
Lifespan
Age (juvenile)
Age (from birth to death)
Age (embryo)
most of Europe and Asia, various forests, steppes and tundra
Wanderers
Horn size
algae
far from shore, deep water, large whales and sharks live here
world of Australasia
Jubilee = every 10th birthday
Earliest developmental stage inside an egg or womb.
Business sausages
Lifespan average
young after fast growth
Juvenile stage following larval metamorphosis but not yet adult.
Horn color
What do they look like?
Maturity
emergence (insects)
end of lifespan
live echinoderms, sea stars, urchins, sea cucumbers
How do they live?
fertilization / egg laying
How do they behave?
birth / hatching
metamorphosis / end of larval stage
end of acceleration
the upper illuminated layer of the sea, 0–200 meters
Share
Find a pet...
Mature, fully developed individual capable of reproduction.
Actively hunting and capturing live prey.
Pets
Indomalayan realm
Primary oral structure used to seize, manipulate, or ingest food.
Indomalayan realm
biting
{name} jubilee
cm
Old-timers
Find an animal or breed...
mouth
turns
Rascals
Dorsal fin count
hot Africa south of the desert, many savannas and forests
after fast growth and adult
Litter size
Map data sources: Ecosystem classification — IUCN Global Ecosystem Typology (Keith et al., 2022), indicative distribution maps Keith et al. (2020), https://doi.org/10.5281/zenodo.3546513; Large Marine Ecosystems — NOAA LME Program; Bathymetry — GEBCO Bathymetric Compilation Group (2026), GEBCO_2026 Grid, https://doi.org/10.5285/4f68d5c7-45eb-f999-e063-7086abc036fa; Climate data — Generated using Copernicus Climate Change Service information; Species occurrence data — GBIF.org, Derived dataset "all animals", https://zveriki.com/dataset/dataset.tsv; Terrestrial ecoregions — RESOLVE Ecoregions 2017 (Dinerstein et al., 2017), CC BY 4.0
How to care for them?
Living from 25 to 40 years. Orangutans, bald eagles, African elephants celebrate their birthday twice a year
°C
Not specified
Actively searching habitats to locate food items.
pelagic zone — open water far from shore and seabed
Where are they found?
all seas and oceans
Species lacks any fixed or lasting shelter structure.
from 0.8 to 1.2 kilograms, 0.6 – 1.2 meters
Legendary longevity: over 100 years. Galapagos tortoises, Greenland sharks, ocean quahogs celebrate with family once every 4 years
Offspring
Elders
Bro
Taxons
if born as {name}
biotope of coral and rocky reefs
omnivore
age
water is almost always warm, even in winter you can swim, very hot in summer
birth date
Palearctic realm
no permanent shelter
Close
was
Career from 7 to 15 months. Dwarf hamsters, voles, field crickets celebrate their birthday twice a month
Marine world
marine epipelagic
The basics
Neotropical realm
My weight?
Non-stop carnival: they only live a few days. Mayflies, rotifers, midges celebrate their birthday more than twice a day
primary food sources
teeth
Potential Habitat
marine bathypelagic
d
In husbandry
On the go from 1.3 to 3.5 years. Forest mice, anoles, rainbow fish party on their birthday once a month
Mass
Mosquitoes, fruit flies, small crustaceans hustle for up to 7 months and throw a birthday party every week
Gestation
islands and part of Australia, many unusual animals and plants
Warm sea
{name} birthday
Always hot
No results found
Caudal fin count
On the map
small crustaceans
all life stages
Female ♀
Body color
world of Afrotropics
Map data sources: Ecosystem classification — IUCN Global Ecosystem Typology (Keith et al., 2022), indicative distribution maps Keith et al. (2020), https://doi.org/10.5281/zenodo.3546513; Large Marine Ecosystems — NOAA LME Program; Bathymetry — GEBCO Bathymetric Compilation Group (2026), GEBCO_2026 Grid, https://doi.org/10.5285/4f68d5c7-45eb-f999-e063-7086abc036fa; Climate data — Generated using Copernicus Climate Change Service information; Species occurrence data — GBIF.org, Derived dataset "all animals", https://zveriki.com/dataset/dataset.tsv; Terrestrial ecoregions — RESOLVE Ecoregions 2017 (Dinerstein et al., 2017), CC BY 4.0
Potential habitat modelled from GBIF occurrence data. Map © Zveriki.com, licensed under CC BY 4.0.
birth year
Maturity
sq mm
yr
How similar?
Male ♂
until the celebration
age as {name}
How do they breed?
On the go from 3.5 to 6 years. Hedgehogs, crows, lizards treat themselves to birthday snacks 6 times a year
What if eaten?
Neither
from birth to adulthood
What do they eat?
Where do they live?
Immature individual that has not yet reached reproductive maturity.
Marine world
early young
Hard dental structures used to bite, tear, or scrape food.
world of Afrotropics
Duration
saline marine habitat
This is me
Gamers
aquatic plants and algae
Horn count
How are they built?
marine
shallow near the shore, water rises and falls, crabs live here
mm
Theoretical lifespan
ml
Stars
Link copied
coastal marine zone — shelf, neritic zone
My age?
wk
My size?
Dorsal fin color
Asexual
swap
Southeast Asia and islands, always hot and humid
active predation
Rabbits, falcons, red-eared turtles hang out for 6-9 years and party on their birthday four times a year
Where do they take shelter?
celebrated their {n} birthday
When you would have been born if you lived as {name}
very hot all year round, frequent rains, but sometimes dry
Littoral Zone
Daddies
small crabs, amphipods and other crustaceans
the dark depths of the sea, below 1000 meters
Lifespan maximum
foraging
from development to end of fast growth
Hermaphrodite ⚥
embryo
Length
kg
Observations
◉{N} more on tap