animals
9 bloodstriker dino (mm3) 20 ft
several dragons can burrow
aberrations are decent burrowers
4HD - Fiery Sandhog 20 ft (
http://www.wizards.com/default.asp?x=dnd/fw/20020817a)
5HD - Dustblight 30 ft. (sandstorm)
8HD - umber hulk (including solid stone)
outsiders
2 Gem scarab (mm5) 15 ft
3-15 xorn are earth gliders
3 tirbana drowser (mm5) 20 ft
4 Rylkar madclaw (mm5) 20 ft
13 Adaru (mm5) 30 ft including solid rock
earth elementals have earth glide
3 thoqquas leave usable tunnel
magical beasts
4 - bluespawn ambusher (MM4) 20 ft including stone8 - ankheg 20 ft
8 - avalancher
12 - bluespawn burrower (MM4) 20 ft.
vermin
6 knell beetle lesser (mm3) 10 ft.
12 knell beetle 10 ft.
plant
12 burrow root (mm5) 20 ft; speed burrow 3x day as immediate action (Ex quality)
18 oaken defender 10 ft loose soil