The Strange Stoppers are among the groups have tried to do what Odd Squad does. Ms. O mentioned them in Odd Squad the Movie and said nothing more about them. The Strange Stoppers wear a purple or violet unifosrm similar to one of the uniforms that Soundcheck wore in their music video for Take Away Four.
This is all that has been said about them.
"Agents, this is not the first time someone has tried to do what we do. There's the Strange Stoppers, The Peculiar Pack, and Rod Squad." --Ms. O --Odd Squad the Movie (12:05)