Diglett's Dig animation from the ground rather than from off the screen.
The Bide glitch is a minor natural glitch in Pokémon Red, Blue, Yellow.
The stored damage from Bide can hit (but not always) a Pokémon under the invulnerable stage of Fly or Dig. If Bide deals damage to a Pokémon under Fly or Dig, the game will reveal its sprite early. This also causes a small animation glitch with Dig where it appears that the enemy Pokémon rises from the ground off the top of the screen instead of the enemy rising up from 'underground'.