A classy seal who attacks quickly, endures attacks without flinching, and deals decent damage. It is recommended to use defensive cat units in tandem with fast-hitting units to defeat this enemy.
It was known as "Sir Baby Seal" in the old English version.
Strategy
At the first time you meet Sir Seal in Greece, use Axe Cat combined with meatshields, Fish Cat and Lizard Cat. This way, Sir Seal will be defeated quickly and easily.
Some time later on in SoL, Sir Seal's strength magnification will fluctuate a lot and give him generally higher strength magnifications than the other enemies introduced in Empire of Cats (i.e. Upset Rock) so use strong anti reds such as Whale Cat/Island Cat. If you have an anti-red Uber, Sir Seal becomes much more manageable.
Dictionary
English Version
Came to the big city from the quiet seaside. Wanted more attention so dyed his body red.
Japanese Version
Encyclopedia entry.
translation
ちまたでウワサのアザラシに憧れて
上京してきたアザラシ。
チヤホヤされたいのになかなか
注目されないので体を赤く染めてみた。
I longing for seals of rumors
A seal that has come to Tokyo.
It's pretty easy although I want to be challenged
I did not draw attention so I dyed my body red.
Variants
Sir Metal Seal (Metal)
Sir Seal's Metal variant, with higher attack rate, damage and health, as well as having the usual attributes of a Metal enemy.
Imperator Sael (Alien)
Alien version of Sir Seal. It is much stronger and can slow the movement of Cat Units.
Zir Zeal (Zombie)
Zombie version of Sir Seal. It has much higher stats in all areas than Sir Seal, combined with a Freeze ability and the regular Zombie-type abilities.