File Island: The Complete Digimon Electronics Resource

Version 3

***Baby***
To get Poyomon:
Born from Egg.
To get Tokomon:
Poyomon: Wait about 60 minutes.

***Child***
To get Patamon:
Tokomon: 0-3 Calls.
To get Kunemon:
Tokomon: 4+ Calls.

***Adult***
To get Unimon:
Patamon: 0-3 Calls, Train 48+.
To get Kentarumon:
Patamon: 4+ Calls, Train 5-31, Overfeed 3+, 0-4 Sleep Disturbances.
To get Ogremon:
Patamon: 0-3 Calls, Train 0-47.
Kunemon: 0-3 Calls, Train 48+.
To get Bakemon:
Patamon: 4+ Calls, Train 32+, Overfeed 3+, 0-6 Sleep Disturbances.
Kunemon: 4+ Calls, Train 8-15, Overfeed 0-5, 5+ Sleep Disturbances.
To get Shellmon:
Kunemon: 0-3 Calls, Train 0-47.
To get Drimogemon:
Kunemon: 4+ Calls, Train 16+, Overfeed 6+, 0-4 Sleep Disturbances.
To get Sukamon:
Patamon/Kunemon: When you do not fulfill the requirements of other Digimon.

***Perfect***
To get Andromon:
Unimon/Ogremon/Shellmon: Fight 15+ battles with a victory ratio 80% or more. (unconfirmed)
To get Giromon:
Kentarumon/Bakemon/Drimogemon: Fight 15+ battles with a victory ratio 80% or more. (unconfirmed)
To get Etemon:
Sukamon: Fight 15+ battles with a victory ratio 80% or more. (unconfirmed)

V-Pet Version 3 Evo Chart
Click to Enlarge

For reference:

The counters are reset when the Digimon evolves. So, for example, nothing that happens to the newly hatched Digimon affects growth at all.
The requirements for Perfect Digimon are unknown at this time. Some battles are necessary.

When its hunger hearts run out, the call icon lights up. If you don't feed it for 20 minutes, it goes out again, and that's a care mistake. The same for strength. However, if BOTH hunger and strength run out, it's still only one care mistake. And if you leave it for a few hours before feeding it, and it bleeps again a few times, then even then it's only one care mistake.
Lights calls are straightforward - leaving the lights on for 20 minutes after it falls asleep is a care mistake.
Accumulating up to 4 piles of poop has no effect at all. (Larger quantities are unknown.)

Only successful training is counted for evolution.

To overfeed, stuff the Digimon with food until it won't eat any more. It is necessary to wait until it loses a hunger heart before overfeeding it again.

Wake the Digimon up by going into the Food menu, training it, or selecting the Battle option.
If you want to wake it, without this being counted as a wakeup, then set the clock to some time during the day. The Digimon will wake up, with no effect on the counters.