I know that Water Terrain is considering Hindering Terrain for movement purposes and that it is not considered Hindering for any other purposes per the rulebook. However, if a specific character card mentions Hindering Terrain, is Water considered Hindering Terrain or not?

For example, Tippy-Toe's Movement Special reads:

If an opposing character within eight squares and line of fire of Tippy-Toe were occupying printed Water Terrain, would that satisfy the requirement of the card to allow him to do a point of damage to that character?

Thanks.

You kinda answered your own question.Water terrain is NOT hindering terrain. It only ACTS like hindering if you move through it. Tippy Toes power would not trigger.

The power you quoted specifically says printed hindering terrain, so water would definitely not count, even if water terrain was considered hindering terrain for purposes other than movement.