A single word connects all of these images:
What is the word, and what are the connections?
How appropriate that there are...
...7 pictures...
...as what are pictured are...
...allusions to the number 7.
Picture by picture   (trail-of-clues commentary tagged on in response to a comment) :
One of the 7 seas.
The initial hunch from pictures 5 and 6 was reinforced by this   ↑   ocean and that   ↓   rainbow, in particular, whose details are still fresh from dealing with Two many rainbows?.
A rainbow with 7 nominal colors.
Gimli, from The Lord of the Rings,
“a remote descendant of Durin the Deathless, chief of the 7 Fathers of the Dwarves.”a dwarf, which brings to mind Snow White and the 7 Dwarfs.
(   ↑ Saved for last, using pure image look-up and word searching. Got l u c k y ! Clues like this are the most thrilling, when they fit into place, that is.)
A sloth, named after one of the 7 capital/deadly sins, also featured as scary graffiti in the movie Se7en.
  ↑ That face keeps showing up at the ends of some of the more unusual mammalian necks in nature documentaries. It took the suggestiveness of other clues to think of the thematic connection, but there it was.
7 of Nine, a reformed Borg in the TV series Star Trek Voyager.
  ↑ This was the clue that got me going as, fortunately, I could only remember the name of the character but not of the actor. So the pyramid   ↓   compounded that into a hunch.
Khufu’s pyramid at Giza, one of the 7 Wonders of the Ancient / Modern World.
 7.   A zipper, as in the compressor/archiver 7-Zip.
As for this puzzle’s title:
7 is considered a number that brings...
...“Good luck!”