Travel Form, formerly known as the "cheetah", is a druidshapeshiftingspell learned at level 16. The form it choose depends on the environment the druid is currently in and whether flying is permitted in that area.
With the release of Mists of Pandaria, the default cheetah form was replaced by an updated stag form. The old cheetah form can still be acquired through the use of Glyph of the Cheetah.
You can not use abilities in this form. You are also considered a Beast, so spells that target Beasts can be used on you (Hibernate, for instance).
Your caster form will start regaining mana 5 seconds after you change to travel form.
Travel Form has three specific advantages over a mount.
Unlike a mount, which players cannot use while in combat, a druid is able to shift into travel form while fighting either a mob or another player.
Travel Form is instantly cast, making it even better for those sticky situations. With Travel Form, druids are able to escape from nearly any fight or simply put distance between themselves and their attackers practically whenever they wish.
As with any form, herbs may be harvested through herbalism, dead beasts can be skinned through skinning. This makes it an excellent way to achieve the fastest results with a gathering profession.
This article or section includes speculation, observations or opinions possibly supported by lore or by Blizzard officials. It should not be taken as representing official lore.
It is widely speculated that the original intention was for this form to be a stag but was changed at the last minute. This is evidenced through the odd hoof-shaped icon, and the fact that while the other forms (except Tree of Life Form) have unique skins, cheetahs that look identical to travel form exist in the game.
Patch 6.0.2 (14-October-2014): Travel Form now automatically transitions between Aquatic, Land, and Flight forms depending on the Druid’s location.
Patch 5.0.4 (28 August 2012): Now uses a stag model rather than cheetah as default.
Patch 4.0.6 (8-Feb-2011): Entering or leaving a shapeshift no longer cancels root effects. It continues to cancel movement slowing effects.; Druid forms now have an Archaeology Survey animation.
Patch 3.2.0 (04-Aug-2009): Can now be learned at level 16.
Patch 1.6.0 (12-Jul-2005): Shapeshifting will now counteract the slowing effects of frost-based spells (Frostbolt, Frost Shock, Cone of Cold, etc.). Druid shapeshift form buttons are no longer dimmed while under the effects of Polymorph.
Patch 1.4.0 (2005-05-05): Shapeshifting into an animal form will now remove Polymorph effects.