My guess is Newfoundland number #57 which came out in 1867 and shows a Newfoundland dog head portrait with his tongue hanging out . I think it is delightful.
Newfoundland
A Penny Black was a postage stamp. It first was issued in Great Britain on 1 May 1840.
That would depend a great deal on how you define a 'cartoon character.' In 1995 the US issued Scott #3000, a sheet of 20 stamps commemorating a dozen of the early American Cartoons, some of which are still running in newspapers today. The first cartoon character is arguably the one issued in 1984 that pictured McGruff, the crime dog. Bugs Bunny was the first animated cartoon character to appear on a US postage stamp in 1997.
The Cheeky Dog was the first webkin ever made.
a dog
No dog has ever set foot (paw) on the moon.
thomas a. callindder
Buck bundy
All Hal had ever wanted was a dog.
No woman or dog have ever landed on the moon.
No dog has ever been launched to the moon.
No dog has ever been launched into space from the USA.