How can I get rid of Elder Guardian?

I've downloaded quite a few mods, so I can't pinpoint which mod could be the cause of the problem. But in a few of my worlds, I'm being "haunted" by an elder guardian. There are also invisible enderman all over the place. Not literally but in various places in my worlds.

I tried doing the /kill @e[type=Creeper] command on the elder guardian(replacing creeper with elder guardian or guardian), but the only problem is that it says that it's not found. Like there are none on the server. I'm also in a flat world, since I got out of my other world which had water. I tried the command on several entities, such as the slime and enderman and it worked. But it won't work on the elder guardian and it's driving me crazy.

I want to find a command or something that can get rid of it for good. Any advice?

Solution 1:

While I can't say it will work as you said you have mods loaded, in vanilla they can be killed with command: /kill @e[type=elder_guardian] if they are loaded.