Emeraldfish Boss

The Emeraldfish Boss is a special version of the Silverfish which is 3 Times as big, it can be summoned by placing an Emerald Block on top of a Monster Block and then giving Redstone Power into the Monster Block. The Boss has 250 Health, deals 4.5 Hearts of damage on Hard Difficulty, 2.5 on Easy, 3.5 on Normal. The Boss can summon Silverfish by making blocks around it Monster Blocks, and then revealed when you hurt it. The Boss can also Burrow into Blocks underneath you and then come out behind you. The Emeraldfish is immune to Fire, Potions, Knockback and Lava, and even Regenerates regularly, but it does have a huge Weakness, Bane of Arthropods!

When defeated, the Emeraldfish would drop 5-15 Emerald Blocks and 50-150 Experience Points. This boss would be cool to add because it would be another new Boss finally added to Minecraft and it would also make Bane of Arthropods Very Useful, instead of just occasionally 1-hit-killing only specific mobs.