At least their unique vantage point means they can see each other without the others seeing them, but he waits for Clint -- considerably smaller and stealthier -- to make his way over, and when he does, he shows him the device, then points at the big reptilian man and whispers as quietly as he can, "Mouse". Hopefully, Clint will get the idea.

He adjusts the settings, although he's not sure he'll actually get a mouse out of it, but at least it will be something smaller and less angry than a crocotank. Maybe it'd turn into a tiger and maul the others. That'd be cool.

He hands it to Clint and pantomimes pushing the trigger button on it and throwing it at the big guy. Hopefully Clint understands because Jim's going to go find that weapon he saw.