On RuneScape gold top of that,Hellhounds don't drop much in terms of valuable loot. You may occasionally get an Ensouled Head,clue scrolls,or a rare Smoldering Stone,but these don't offset the amount of time and effort spent fighting them. As a result,Hellhounds are an inefficient choice for a Slayer task and should be blocked early.
Cave Krakens

Cave Krakens are another monster that should be avoided. They have a high Slayer task weight,meaning you're likely to encounter them frequently. But despite the frequent assignments,Cave Krakens are slow to kill. Since you can only kill them with magic (preferably a Trident of the Swamp),these tasks tend to take longer than many other monsters. Additionally,their drop table is relatively poor,so you won't be earning much GP from these tasks.

The high task weight and lack of efficient XP gains make Cave Krakens prime candidates for the Block List. Blocking them will save you a lot of time in the long run,allowing you to buy OSRS GP focus on more rewarding tasks.