Dwebble (557) White: It makes a hole in a suitable rock. If that rock breaks, the Pokémon remains agitated until it locates a replacement.

Ferroseed (597) White: They stick their spikes into cave walls and absorb the minerals they find in the rock.

Dwebble height 0.3 m and weight 14.5 kg including the stone, of course.
Ferroseed height… 0.6 m and weight 18.8 kg… poor Dwebble.