22 cards where the text includes “mountainwalk” and the card types include “creature” and (the card is available on Paper)

Canyon Wildcat (Duel Decks: Ajani vs. Nicol Bolas #6)
Cave People (Fifth Edition #215)
Cavern Crawler (Mercadian Masques #181)
Cliff Threader (Zendikar #7)
Colos Yearling (Urza's Destiny #79)
Dwarven Grunt (Odyssey #185)
Dwarven Pony (Homelands #70)
Enslaved Scout (Alliances #71a)
Glissa's Courier (Mirrodin Besieged #80)
Goblin King (Tenth Edition #207)
Goblin Mountaineer (Shards of Alara #102)
Goblins of the Flarg (Chronicles #51)
Goblin Spelunkers (Ravnica: City of Guilds #128)
Hillcomber Giant (Modern Masters #18)
Mountain Goat (Classic Sixth Edition #195)
Mountain Yeti (Chronicles #53)
River Merfolk (Fallen Empires #24)
Rock Badger (Tenth Edition #226)
Sokenzan Bruiser (Champions of Kamigawa #188)
Vug Lizard (Urza's Saga #227)
Zodiac Dog (Portal Three Kingdoms #130)
Zodiac Goat (Portal Three Kingdoms #132)

It is the moment of discovery, the triumph of the mind, and the end of these results.