First Appearance: Tough Kid Squad #1 (March 1942).
Golden Age Appearances: Tough Kid Squad #1.
Modern Appearances: None.
Years Active: 1942-?

I'm going to turn over the reins of narration for this group to the formidable Ronald Byrd, who describes the Tough Kid Squad so much better than I could:

The Tough Kid Squad (from the one-issue of the same name) consists of Wally and Tom Danger, Butch (the fat kid; evidently his parents expected him to turn out to be the tough kid), Derrick Dawes (the actual tough kid), and Eagle (Timely's first and, mercifully, only Native American kid (think "-um")).  Our main focus is the Danger kids, identical twins, who were orphaned as infants back in 1926, when one Doctor Klutch, business partner of the twins' scientist father Doctor Danger (no relation, one assumes, to the magnet-wielding opponent of Kid Colt; how often do you see just a run-of-the-mill scientist with a name like that?), has the doctor and his wife killed as part of his plan to assume sole ownership of a serum that enhances human development (in 1926? huh).  Separated, the two are adopted by very different men:  Wally is raised by the scholarly Professor Moxon, while Tom falls under the influence of the criminal Wong Chee (the Fox), who calls him "Little Owl" (that whole Asian thing, you know, grasshopper). Both boys, as it happens, received the (well let's just call it a) super-serum before Doctor Danger's death, so that Wally is unusually smart, Tom is unusually strong (and scrappy, so that we have two tough kids on the same team, which seems redundant), and both are quite fit.  Actually, both may have full enhancement, but the fact that Wally was raised by a scientist and Tom by a criminal may have led to the development of each one's given specialty.

Jump ahead fourteen years (or a little more; Tough Kid Squad #1 was published in 1941), when Wally is entering Westcliff School.  At this time, Tom rebels against Wong Chee and sets out on his own.  Naturally enough, the twins meet, and Wally arranges for Tom to enter school as well (They are so identical that Wally takes the entrance exam twice in order for Tom to have a high score.).  They join the football team and become fast friends with Butch, Derrick, and Eagle (Eagle's stereotype aside, it's nice that he was allowed to ATTEND a good school, we've got that, anyway, although he must have been the despair of the grammar department.).  However, the publicity from the game calls the twins to the attention of Dr. Klutch, who still hasn't quite figured out the serum.  I won't insult your intelligence by suggesting that you can't deduce how things proceed from here.