This is the 1978 DC Calendar, focusing on "Super-Spectacular Disasters". Original price: $4.95. Cover is by Neal Adams. The calendar featured various heroes fighting villains not typically known as theirs, such as Green Lantern and Green Arrow vs. Queen Bee, Aquaman vs. Weather Wizard, Metal Men vs. Ocean Master, and Wonder Woman vs. Quakemaster.
The Legion page, for December, features Karate Kid leading a contingent of Legionnaires against the Toyman in the 1977. Helping him out are Lightning Lad, Saturn Girl, Sun Boy, Colossal Boy, Princess Projectra, Cosmic Boy, Brainiac 5, Shadow Lass, and Chameleon Boy. Art by Sherman and Abel, the regular art team for part of 1977.
The unreadable text in the calendar:
Dec. 6: At a major New York department store, the TOYMAN replaces Santa Claus -- without anyone knowing!
Dec. 9: FACT FILE: The LEGION OF SUPER-HEROES first appeared in ADVENTURE COMICS #247 (April, 1958).
Dec. 11: FACT FILE: The TOYMAN first battled SUPERMAN in ACTION COMICS #64 (September, 1943).
Dec. 16: The LEGIONNAIRES decide to spend an "old-fashioned" Christmas this year -- and plan to journey from the 30th century to 1977!
Dec. 21: KARATE KID welcomes his fellow LEGIONNAIRES to his 20th century home!
The "computer readout" text tells the reader to fill in a square on a matrix, which when filled out will reveal the mystery mastermind behind all the attacks. I'm not going to tell you who it is, but if I say it's a certain bald-headed bad guy you could probably guess.