Mud Slinger - 4MM Creature
1 attack, 3 health, 3 movement, 3 sight, 2 range

Any creature who is damaged by the Mud Slinger has their vision reduced to one.

I would decrease its movement and increase its range by one.

I'd like to see the effect having a lifespan on it... the target can clean it's face after a turn or two.. perhaps use the Reload mechanic [Dagg Cannon, among others] or just have the effect put a blindness token or two and remove a token per turn.

I agree Mist... it should be temporary blindness. Two rounds seems appropriate.

I know this would be extra work, but I don't think Mud Slinger should be able to use a ranged attack against swimming creatures... or not be able to attack non-aloft creatures in a water tile in general.