You have a thread hill, but the hill is a bit weird looking (take a look at the hill radical in this kanji). It's not any normal hill, it's a weird lumpy hill that isn't quite right. That's because it is a thread hill of netting, and parts of the nets have caught things, like fish and cats, so there's weird abnormal lumps in them.
There's so much netting that it's out of control. You decide to take your lawn mower to mow (もう) it all down.