A necromancer, of course, raises the dead for nefarious purposes.
Do you know that there are vivimancers among the dead, who call to them those who can make them live again?
The quote above is from Chapter VII, Attractions from The Sword of the Lictor (1982), third book of Gene Wolfe's The Book of the New Sun tetralogy. Surely vivimancers should be in The Great Chain of Being somewhere, but scarce anyone but Gene Wolfe seems to know of them.

Robert J. Hall gives a different meaning under 'College of Vivimancy':

Adepts of this college use their intimate knowledge of primal forces of life to create, mutate, and ultimately enhance living things.
(http://hiddenway.tripod.com/hero/vivimanc.html)

There are vivimancers mentioned in various RPGs, but online sources do not give definitions. Vivamancer and Vivamancy seem to relate to healing, as do Vivomancer and Vivomancy.