It is a Tern
Any of various sea birds of the genus Sterna and related genera, related to and resembling the gulls but characteristically smaller and having a forked tail.
Source: Answers.com
Roan: definition:
1. an animal, especially a horse with a roan coat.
2. the color of a roan animal
3. having a reddish brown, brown, or black coat speckled with white or gray hairs.
A tern is a seabird with four letters that ends in N.
tanager, thrush, turkey
tern
Pigeon
Thrush
newt
tern
Barb
into
a kravdraa
puma
crab
the furniture store kika
Panda
Rose. Rene
Duty has four letters and starts with a D, and ends with a Y.
pets
An animal having four feet is a quadruped which means four-footed or having four feet.
Ogre - as in Shrek