Where did the slugs that afflicted Ron come from when he was under the slug vomiting charm? Does the charm create life, or were the slugs plucked from somewhere else and placed inside Ron?
This seems a common thing in HP spells - Avis was used to conjure birds by Hermione and Ollivander, they transfigured inanimate objects into animate - see full list on the Wikia, Bat Bogey Hex was used to create bats from snot etc...
Also, spells were used to conjure/create flora - e.g. flowers to put on Harry's parents grave conjured by Hermione.
The canon was never very clear on whether this was life creation permanently, life creation temporarily, or transporting existing life from someplace else.