Marvel Team-Up #78 was published by Marvel Comics (natch) in February 1979. The issue was written by Bill Kunkel, with artwork by Don Perlin & Frank Giacoia. "Claws!" immediately pits Spidey and Wonder Man against the Griffin, a supervillain who has been genetically modified by the Secret Empire to have enhanced strength, wings for flight capability, a spiked tail and leonine claws.
After the Griffin arrives at Avengers Mansion to seek revenge on the Beast, he encounters Simon "Wonder Man" Williams instead. [Spidey and the Beast had tangled with the Griffin (aka small-time punk, Johnny Horton) in a previous issue of Team-Up (#38)]. This issue takes place during the period when Wonder Man was suffering some serious self-doubts about his role as a superhero, and the Griffin pretty much gets the best of him before the webslinger arrives to lend a helping hand. However, something isn't quite right with the Griffin and he flies off in the middle of their battle. Spidey brings "Wondy" up to speed on the Griffin's origin and then heads out to find the rogue.
When Spider-Man realizes that the Griffin actually "wants" to fight the combined Avengers team in order to allow his serum to further enhance his genetically-modified powers, he intends to warn Wonder Man, but oops, the Griffin quickly returns to wipe the floor with the wall-crawler. Fortunately, Wonder Man borrows a flying sled from Tony Stark and blasts the Griffin with an energy beam. Then things take a turn for the worse when the Griffin evolves even further into a powerful bestial state as a result. Roaring in defiance as he begins to lose his grip on humanity, the Griffin lifts Wonder Man's aircraft to hurl it at the two heroes, but his powers aren't stable enough to support the vehicles weight and as the damaged craft burns, the Griffin collapses underneath it, ending their titanic battle.
Kunkel's story gets right down to brass tacks and is fairly intense from the outset, and the art team of Perlin and Giacoia provides exciting page layouts and dynamic superhero action from start to finish. The earliest issues of Marvel Team-Up may garner the lions share of attention from collectors, but these latter issues are really worth checking out and they can be gotten for very affordable prices for the patient fan who likes simple pleasures.