5e sadly doesn't have all epic creatures which you can reanimate as a necro? Red dragon can be raised like a bone dragon, for ex. Or not?
Only IF the DM allows it.
But in general, you can only get low CR zombies/skeletons.
On 5e, wotc not only took alway OHK spells like Finger of Death and Wail of The BAnshee but also took alway more powerful summons and was able to create powerful undead (
http://www.d20srd.org/srd/spells/createGreaterUndead.htm )
Old editions also had a lot of animating spells
Animate dead
Create ancient dead
Create baneguard
Create crypt servant
Create crypt thing
Create death tyrant
Create direguard
Create shade
Create undead
Create undead minion
Create watchghost
Undeath after death
