Ugly Fish was added in Beta 9.2. Previous Versions can be found here.
Whenever Ugly Fish damages an enemy monster, that monster will gain -2 ATK. This can be used while defending as well as attacking. This is very good, especially since Ugly Fish has Haste. This means that you can use its effect right away. And because of its decently high HP, it has a high change surviving after a single attack.
Trivia
- When it was first released in Beta 9.2, the card was bugged and would only drop ATK by 1 instead of 2. Beta 9.3 fixed it.
- When Beta 13.1 changed its ability from Taunt to Haste, the patch notes stated it would also be turned into a 2/8 monster. This, however, was not done right away. It stayed a 3/7 at first, then turned into a 2/7 and lastly into a 2/8.