Morph Hopper (3.5e Feat)
From D&D Wiki
Morph Hopper [Special]
Hops around to avoid difficult terrain
Prerequisite: Dex 13, must be able to change shape in one of the following five ways: change shape supernatural ability, shapechanger subtype, polymorph as a spell-like ability, able to cast the polymorph spell, wild shape or similar class feature
Benefit: You can charge through terrains that normally hamper your movement, and your movement is not hampered as much by difficult terrains and obstacles (can move at normal speed when terrains makes you move at half speed, movement is still hampered if it makes your speed drop to a quarter of normal).
Normal: You cannot charge through terrains that normally hamper your movement. When you move through difficult terrains and obstacles, your movements are slower (see table).
Special: If you cast the polymorph spell, has polymorph as a spell-like ability usable less often than at will, or has the wild shape class feature, then this feat loses function when you cannot use them.