Huh, I thought it was a Hunter X Hunter reference with the huge tree (wasn't metal though). One of the chimera ants is mixed with a shrike and impaled it's victims as well. Got taken out quick though, once spoiler spoiler spoiler, so wasn't that important an antagonist.
I'm fairly certain it is, I've seen it 'confirmed' on Reddit in the past.
We have a variety locally, used to feed them raw meat as kids. Fascinating to watch them store and work their meals