A seagull is one of the many 23-24 animals available. A seagull is usually found around beaches. Killing one gives you raw bird meat, which when place in a furnace gives you cooked bird meat.
Seagulls are pure white with an orange beak and legs. A seagull's egg spawner is pure white as well. Seagulls, like all birds, get intimidated when you run up to them and will fly away. Putting Sneak Mode on will solve this problem.