In Warcraft III.
A seal is an amphibious, but primarily water dwelling, beast or critter found along the shores of Azeroth. The tuskarr of Northrend use domesticated seals as draft animals to pull their sleds.
First seen as critters in Warcraft II and Warcraft III, they are usually seen frolicking in the waters or sunning on the coasts.
In Warcraft II.
Warcraft III animation.
Warcraft III portrait.
Warcraft III: Reforged icon.
Warcraft III: Reforged concept art.