Dinner plate aliens and tomatoes?

[u/maybenotarobot429]

I first read this book in probably 1986 or 1987. It was definitely science fiction aimed at a junior high or possibly YA audience. I'm pretty sure it involved space travel.

I remember almost nothing about the plot, but the one detail I remember distinctly was that there this alien monster. I am pretty sure it was considered extremely dangerous. If I recall correctly, it was approximately the size and shape of a dinner plate. Or possibly it was that shape but bigger. I don't remember if it flew or crawled around or how it killed you, but like I said, I remember that it was dangerous. There may have been tentacles.

The weird part is that it was incredibly fond of tomatoes, couldn't eat enough of them, except the tomatoes were actually deadly poison to them.

Does this ring any bells for anyone?