It's "and/or," not "and/or/nor." Barring something else affecting it, it will always be a Turtle, an Elephant, or both
This is a great 2-for-1
Once played, it allows you to gain health for each other creature summoned while Trostani is on the battlefield
it gains you life, trades with almost any creature on the board, and leaves a literal army behind for your opponent to deal with
Toss in a Mirkwood Bats or Mayhem Devil, and you've got a powerful engine to drain your opponents into oblivion
For example, if it has three age counters on it, you may put four cards from your graveyard on the bottom of your library and two cards from your opponent's graveyard on the bottom of their library