The basic IdleState used by the Maw Flower enemy is really simple.

It just has a Serialized Field for an animation which it plays when the state is entered:

public class IdleState : CharacterState
    [SerializeField] private ClipTransition _Animation;

    public override void OnEnterState()

Since this will be the character's starting state, it also has an OnValidate method to apply the currently assigned animation's first frame so that the character in the scene automatically shows the first Sprite of their Idle animation:

    protected override void OnValidate()

The base CharacterState has a MovementSpeedMultiplier property which states can override to allow movement, but since IdleState doesn't it will always return 0:

public virtual float MovementSpeedMultiplier => 0;