SOLUTION: SQUISH LISTANSWER: FREE FLOAT
The first step of this puzzle is identifying the fourteen given Squishmallows; reverse image search is very helpful for this step, and the Squishmallows are given in alphabetical order as an additional aid. After identifying some of the Squishmallow names, solvers may notice that some of the names can be paired up to make names of fictional characters. Indeed, the big "aha" of this puzzle is that these Squishmallow names are the first and last names of seven characters from the DC Comics universe, as hinted by "dynamic duos" in the flavortext:
As solvers identify the seven characters, they find that the sets of blanks don't fit most of the character names. The last step of this puzzle, as shown in the image above, is identifying the alter egos of these characters, which do fit into the blanks. The answer can be formed by reading off the letters on the numbered blanks in order, which spell FREE FLOAT.
This is the only puzzle that was not in the original version of this hunt; I had written a puzzle about jellyfish where species' common names were arranged in a grid and had to be labeled as safe or unsafe to touch, with a thematic Braille extraction. The main obstacle is that sources on what jellyfish species are "safe to touch" differ, and there was no single source to reliably use as canon. I was able to confirm the intended safe/unsafe labels face-to-face for my partner, but I knew that a completely different puzzle had to be used here.
This puzzle was originally written for a hunt that ended up getting scrapped, with much more legwork (there were sixty Squishmallows, and the names were taken from several categories including literary characters, actors, and musicians. I really love the final version, and have taken this as a lesson in paring down really bloated puzzle ideas. (Sidenote: Squishmallows have so many names that this wasn't nearly as constrained a puzzle as it might look, although it is unbelievable that there are no Squishmallows named Allen, Kent, or Wayne, yet Dent the Dragon is somehow a real Squishmallow.)