* [[Indigo rune]]: Changes the skill to a rain of toads, which fall down on the targeted location.
* [[Obsidian rune]]: Summons a single, huge, stationary frog that uses a sticky tongue to capture and consume monsters in one gulp. It spits out the treasure and items. The mega-toad can eat [[Champions]] (possibly only at higher/highest rune level?), but not [[bosses]] or (presumably) bigger enemies.
===Hydra===
[[File:Runes-hydra-all.jpg|thumb|400px|Hydra skill rune effects.]]
The rune functions for [[Hydra]], a [[Wizard skill]] were revealed during a panel discussion at Blizzcon 2010. The basic skill summons a fiery dragon that breaks through the earth and spits firebolts at nearby enemies.
* [[Alabaster rune]]: Turns the Hydra purple and the damage type to Arcane.
* [[Crimson rune]]: Turns the Hydra blue and the damage type to a short-range chilling frost spray.
* [[Golden rune]]: Creates a giant hydra that deals higher damage via AoE Firewalls.
* [[Indigo rune]]: Turns the hydra blue and the projectiles to lightning balls that never miss.
* [[Obsidian rune]]: Turns the hydra green and the damage to a splashing poison acid.
This Hydra information was revealed at Blizzcon in October 2010. It shows changes even since August, when one of Hydra's rune effects was a faster/multishot, instead of the Acid element.
These bonuses also show how unpredictable the effects are. By previous knowledge and logic, Crimson should be the +damage/firewalls effect, since it generally adds damage and/or fire effects. Possibly the developers are shuffling rune bonuses around randomly, in order to make the runes equivalently useful. Rather than, for instance, allowing Crimson to be the most useful and Golden the least, on the whole.
