In addition to its serviceable attack pool and movement speed, Mooth has a repetitive but unorthodox attacking technique where it winds up, rams your cats, and lowers down, all taking a little over a second to execute.
The damage-dealing part of Mooth's one-second attack animation is right in the middle, so if new players spam cheap cats that have a quick cooldown period, they will discover that Mooth's pushing power is greatly lowered. This tactic is often referred to by not-so-new players as 'meatshielding,' and will be expanded upon later in Empire of Cats, hint hint.
In the Legend Stages, Mooth's position as a backline enemy is quickly stolen by Owlbrow, an enemy who behaves similarly to Mooth but moves slower and has more attack power in proportion to its health. You'll still be seeing plenty of Mooths in your adventures, because this enemy drops a large amount of money when defeated, and many stages later in the game use Mooths as a money provider.
Strategy
A good method to defeat Mooths is to overwhelm it with fast-hitting units, like Cow Cat, or using Lizard/Gross Cat, since they outrange it. This enemy is Floating, so anti-Floating cats are useful against him.
To kill it, you need strong attackers like Titan Cat or anti-Floating cats like Mer-Cat. If you have real trouble with it, use Macho Cat and Wall Cat to stall it, then use Dragon Cat and Mythical Titan Cat.
Dictionary
English Version
He dreamed he will become a beautiful butterfly in the future.
Found out the truth and now rebelling against nature.
He said that he will become a beautiful butterfly in the future
When expectation comes out of the pupa,
I was shocked by what was "Ga".
There was also a period of falling but now we are rehabilitating.
Variants
Maawth (Alien/Floating)
Alien version of Mooth. It is stronger, has longer range, and can stop Cat Units.
Othom (Relic/Floating)
Relic version of Mooth. Far stronger with Omni Strike and a guaranteed chance (100%) to curse Cat Units.
Sister Lione (Floating)
Event variant of Mooth. Has more health and range plus guaranteed chance to decrease cat unit´s attack power at half, but it has half the movement speed and 5 knockbacks.