There have been so many variants of the clone effect since the original Clone in Limited Edition Alpha, whether it's got flash like Stunt Double, shifts power and toughness like Gigantoplasm, makes it an illusion like Phantasmal Image, allows it to copy planeswalkers like Spark Double, or many others
Players specifically want to look for the Gengar ex card, which has a few different prints
Milling had definitely been established as part of artifacts' slice of the color pie (more on this in a bit), so Mirrodin was an excellent block to put more milling artifacts in
With the merger, all non-sports cards will be eligible for grading, including many series that were not accepted previously, such as Garbage Pail Kids, Mars Attacks, Wacky Packages, Star Trek and many more, from 1879 to today