Brainiac
Brainiac (Milton Fine & Vril Dox (merged), DC, 1988-1998) appears in 38 issues in grailworth's catalog, and was first published in 1988. First post-Crisis appearance: Adventures of Superman #438 (1987), cover dated 1988.
First appearance
Origin
Every appearance we value
Showcase '96 (1996) 2 issues
Superman: The Doomsday Wars (1998) 2 issues
Character appearances from the Grand Comics Database, CC BY-SA 4.0.