Horsea is a light blue, seahorse-like Pokémon. It has red eyes, a long, tubular mouth, and three spike-like fins on either side of its head. Its ridged belly and single dorsal fin are cream-colored. Highly adept in the water, it uses its dorsal fin to swim in any direction while facing forward. It has tightly curled tail that it can use as both a balance and an anchor when caught in a strong current. In safer environments, it uses its tail to play with other members of its species.
Horsea feeds on insects and moss gathered from rocks. If Horsea senses danger, it sprays water or dense black ink from its mouth at its attacker. It can shoot more precisely at insects flying above the surface of the water. Horsea nests in coral reefs and islands throughout the ocean. Many Eggs are laid every year, and the young are raised by the male Horsea rather than the female.
In Alola, Kanto!, four Horsea were seen at Professor Oak's Laboratory. A fifth was featured in Lana's fantasy about the Pokémon that she hoped to see in Kanto.
Green had a Horsea in Zap! Zap! Zapdos! on her team that she received from Silver in exchange for her Granbull following their escape from the Masked Man. She used her in her crafty tricks such as cloaking areas with Smokescreen or leaving ink trails. She was later transferred back to Silver, and eventually evolved into Kingdra.
A Horsea appeared in ''Breath of the Dragonair Part 1, under the ownership of a Trainer. It was used in a surfing contest, before it was interrupted by Lance controlling the winning prize, a Dragonair.
Horsea eats small insects and moss off of rocks. If the ocean current turns fast, this Pokémon anchors itself by wrapping its tail around rocks or coral to prevent being washed away.
If Horsea senses danger, it will reflexively spray a dense black ink from its mouth and try to escape. This Pokémon swims by cleverly flapping the fins on its back.
Horsea eats small insects and moss off of rocks. If the ocean current turns fast, this Pokémon anchors itself by wrapping its tail around rocks or coral to prevent being washed away.
If Horsea senses danger, it will reflexively spray a dense black ink from its mouth and try to escape. This Pokémon swims by cleverly flapping the fin on its back.
Horsea's Red and Blue artwork depicting it with two fins instead of one
Horsea and its evolved forms share their category with Dratini, its evolved forms, Salamence, and Goodra. They are all known as the Dragon Pokémon.
Horsea's art work from Pokémon Red and Blue depicted it with two fins instead of one. This two finned design was referenced in Alola, Kanto!
Origin
Horsea appears to be based on a seahorse, though its ability to shoot ink resembles that of a squid. Its species name may be a reference to leafy seadragons, or seahorses turning into dragons after a century in Japanese mythology.
Name origin
Horsea appears to be derived from seahorse with reversed syllables, and a corruption of the diminutive horsie.
Tattu appears to be a corruption of 竜 tatsu (dragon), which is part of the common name of a seahorse in Japanese: 竜の落し子 tatsu-no-otoshigo ("illegitimate child of a dragon").
In other languages
Language
Title
Meaning
Japanese
タッツー Tattu
From the Japanese term for seahorse, タツノオトシゴ/竜の落とし子
TM33 (Ice Punch) (100%)
Dragon Scale (2%)
+ 
For other sprites and images, please see Horsea images on the Bulbagarden Archives.
