In Thor: Ragnarok, Valkyrie was referred to as Scrapper 142 and was Grandmaster's primary warrior. But that digit 142 in her Sakaar name doesn't seem random. Is it some reference or Easter egg? Or am I just over-thinking?
As the question has been raised about the first appearance based on some statement on Wikipedia,
The character first appeared in The Avengers #83 (December 1970) and has become a mainstay of the superhero team known as the Defenders,
here is an excerpt from the issue Avengers Vol 1 #83 December, 1970
Suddenly, Valkyrie knocks out all her comrades and reveals that she is really the Enchantress in disguise. She explains that after her last failed attempt at taking over Asgard failed (in Hulk #102) she and the Executioner were banished to a barren neither world. There, the Executioner abandoned her for the a mysterious woman who appeared to offer the Executioner her love. Feeling betrayed, the Enchantress vowed revenge on all men and used the Valkyrie disguise and the formation of the Liberators to met this end.
It is evident that Enchantress impersonates Valkyrie.
Q.E.D. Valkyrie's first appearance was in Incredible Hulk Vol 1 #142 August, 1971