In an issue I have, GIANT-SIZE MAN-THING 3, Feb 1975 (itself a book that perhaps was still in an era too innocent to fully grasp the connotations of
that title!), also contains a Lee/Kirby/Ayers monster story reprint titled
"Save Me From The Weed!", reprinted from STRANGE TALES 94, March 1962.
The full story in larger size pages at:
https://readcomiconline.to/Comic/Giant-Size-Man-Thing/Issue-3?id=86492#39 It sounds more like a story dealing with drug addiction.
But no, it's a weed-like alien from outer space.