Pokémon HeartGold Version Unlockables

Swarm Pokemon
Like in previous games, there are Pokemon that appear randomly, on specific routes, each day.

In order to keep up with the Pokemon sightings, you'll need to tune into Professor Oak's Pokemon Talk Channel daily.

The chart below shows the various Pokemon that appear in swarms, as well as the routes you'll find them on:
UnlockableHow to unlock
ChanseyFound on Route 13
DittoFound on Route 47
MarillFound inside Mt. Mortar
YanmaFound on Route 35
DunsparceFound inside Dark Cave
SnubbullFound on Route 38
QuilfishFound on Route 32
RemoraidFound on Route 44
PoochyenaFound on Route 1
WingullFound in Vermilion City (Surf)
RaltsFound on Route 34
SwabluFound on Route 45
WhiscashFound in Violet City (Surf)
ClamperlFound on Route 19
RelicanthFound on Route 12
LuvdiscFound on Route 27
KricketotFound in Viridian Forest
BunearyFound on Route 25
SableyeFound on Route 9
BaltoyFound on Route 3