I found a pamphlet compiled and published by The Reader's Digest amongst some old reference works here.
I tried these word teasers and enjoyed the concept.
Thought I'd put them here:
"Kangaroo Words" by Ben O'Dell A kangaroo word carries within its spelling, in normal order, a smaller word that is a perfect synonym for itself. For example, note how the word BLOSSOMS contains the word BLOOMS. See if you can find the synonym hiding in each word below.
How quickly can you find out what's unusual about this paragraph? It looks so ordinary you'd think nothing was wrong with it at all- and, in fact, nothing is. But it is unusual. Why? Study it, think about it, and you may find out. But you must do it without coaching: I'm not going to assist you in any way. No doubt, if you work at it for a bit, it will dawn on you. Who knows until you try? So hop to it, try your skill and pray for luck. Par is about half an hour.
You know I didn't get SLITHERED, but I also sort of missed #8, by misspelling the word I figured was the synonym. (I had *veried*...)
You are much closer to getting #8 than I!