Quoted from Rdoyle1978:The classic “Universal Monsters” don’t always include the Phantom - mostly because the classic Phantom film (the one everybody knows) is silent. It was re-released in the 1950s around when Creature was coming out, when the other films were going through a revival, but it didn’t fare super well (silent movie), and the remake with Claude Rains is nice but it never caught on huge like the other monsters.
The Invisible Man isn’t included either.
... or is he?
<phantom flip> *cough*