Silverfish

Silverfish are a Hostile Mob which retain their typical vanilla behaviour when encountered in SkyBlock. They deal 20 damage.

Location
Silverfish can be encountered when fighting Splitter Spiders or Spider Jockeys in the Spider's Den. The Splitter Spider will spawn two Silverfish on its body when killed. The Spider Jockey will shoot Silverfish from its arrow.

Rune Farming
Silverfish are perhaps the most effective mob to farm Runes off of because of their low health. If the player traverses to the top of the Spider's Den, Spider Jockeys spawn around every 10 seconds. If the spider holding the jockey is killed, the skeleton will stand around and shoot Silverfish at the player roughly once every 2 seconds. If the player leaves multiple Spider Jockeys, they will have multiple Silverfish spawning every second.

To deal with the swarms of Silverfish, the player can utilize a sword with Cleave or a Hurricane Bow or any weapon with a reasonable AOE damage. Both of these weapons will kill multiple Silverfish with every attack. The player should be warned that the large numbers of Silverfish can kill a well armored Mid-Game player and that the incautious player may be knocked from the top of the Spider's Den by the Silverfish. Another useful weapon against them is a Golem Sword (specifically its item ability) as it deals enough damage to 1 shot a silverfish and has a fairly large area of effect, this means it becomes extremely easy to hit all the silverfish at once without trying to hit it's small hitbox. This strategy can also kill the spider jockeys.