Just messing around, and these are the characters I found it hitting with.
Red - Spikes them with the true sweet spot and does 15% damage. These are for those epic grab release suicide kills to win games and be regarded as a hero amongst all.
Green - Hits them with the frontal sweet spot and does 10% damage. These are more practical and can kill fairly early, and are safe as long as you aren't near the ledge really.
Purple - Hits them with the rear sweet spot and does 10% damage. Only a couple are hit by this, but it will be a surprise for them when it hits. Has similar usage as the frontal hitbox.
Normal - Grey text means it doesn't work
Mario - Hits down 15% damage
Luigi - Hits out 10% damage
Peach - Hits out 10% damage
Bowser - Doesn't work
Donkey Kong - Hits down 15% damage
Diddy Kong - Doesn't work
Yoshi - Hits out 10% damage
Link - Doesn't work
Zelda - Hits out 10% damage
Sheik - Doesn't work
Ganondorf - Doesn't work
Toon Link - Hits down 15% damage
Wario - Doesn't work
Samus - Doesn't work
Pit - Hits out 10% damage
Ice Climber(s) - Hits down 15% damage
R.O.B. - Hits out 10% damage
Kirby - Hits down 15% damage
Meta Knight - Doesn't work
King Dedede - Hits out 10% damage
Olimar - Hits behind 10% damage
Fox - Doesn't work
Falco - Doesn't work
Wolf - Doesn't work
Captain Falcon - Doesn't work
Pikachu - Doesn't work
Squirtle -Doesn't work
Ivysaur -Hits down 15% damage
Charizard - Hits out 10% damage
Lucario - Hits out 10% damage
Jigglypuff - Doesn't work
Marth - Hits out 10% damage
Ike - Hits out 10% damage
Ness - Hits behind 10% damage
Lucas - Doesn't work
Mr. Game and Watch - Hits down 15% damage
Snake - Hits out 10% damage
Sonic - Hits out 10% damage
Zero Suit Samus - Hits out 10% damage
Timing notes and other stuff -
Some of the green group can be spiked if you wait a small amount of time before executing the forward B. Examples are zero suit and luigi, I'm sure many others are possible as well.
Wario - If you do get an air release, you should just upsmash him
Meta Knight - You can DACUS his air release
Ice Climbers - Probably won't get many grab releases on these two
King dedede - Strict timing, has to be very precise
Charizard - Strict timing, has to be very precise
Sonic - Strict timing, has to be very precise
Mr. Game and Watch - I was using this in some friendlies today and depending on the timing I was able to get other outcomes as well, but hitting down is the most common. Waiting a bit seemed to net a hit out, and perfect timing I think gave me a hit behind. More testing to come soon on this one.
Grouping -
Red Group 18%
Mario
Donkey Kong
Toon Link
Ice Climber(s)
Kirby
Ivysaur
Mr. Game and Watch
Green Group 36%
Luigi
Peace
Yoshi
Zelda
Pit
R.O.B.
King Dedede
Charizard
Lucario
Marth
Ike
Snake
Sonic
Zero Suit Samus
Purple Group - 5%
Olimar
Ness
Grey Group - 41%
Bowser
Diddy Kong
Link
Sheik
Ganondorf
Wario
Samus
Meta Knight
Fox
Falco
Wolf
Captain Falcon
Pikachu
Squirtle
Jigglypuff
Lucas
**NOTE** These are merely who it hits and how. This does NOT mean they are inescapable by any means. Most of them seem to work as "combos" but I'm sure there are a few that can be air dodged or something. However, due to the nature of this attack, I would not be surprised if the opponent either didn't react fast enough and/or had no idea wolf could hit them from so far away. Honestly these should work most of the time in a real match.
I hope this information hasn't been posted already. I haven't seen it, but there's always that chance. If it hasn't that's great, and I hope you enjoy sweet spotting wolf's forward B as much as I do, cause it's my favourite part of wolf and ultimately why I took the time to test this stuff. Thanks for your time.
*EDIT added the DACUS to meta knight's air release in other infos
Red - Spikes them with the true sweet spot and does 15% damage. These are for those epic grab release suicide kills to win games and be regarded as a hero amongst all.
Green - Hits them with the frontal sweet spot and does 10% damage. These are more practical and can kill fairly early, and are safe as long as you aren't near the ledge really.
Purple - Hits them with the rear sweet spot and does 10% damage. Only a couple are hit by this, but it will be a surprise for them when it hits. Has similar usage as the frontal hitbox.
Normal - Grey text means it doesn't work
Mario - Hits down 15% damage
Luigi - Hits out 10% damage
Peach - Hits out 10% damage
Bowser - Doesn't work
Donkey Kong - Hits down 15% damage
Diddy Kong - Doesn't work
Yoshi - Hits out 10% damage
Link - Doesn't work
Zelda - Hits out 10% damage
Sheik - Doesn't work
Ganondorf - Doesn't work
Toon Link - Hits down 15% damage
Wario - Doesn't work
Samus - Doesn't work
Pit - Hits out 10% damage
Ice Climber(s) - Hits down 15% damage
R.O.B. - Hits out 10% damage
Kirby - Hits down 15% damage
Meta Knight - Doesn't work
King Dedede - Hits out 10% damage
Olimar - Hits behind 10% damage
Fox - Doesn't work
Falco - Doesn't work
Wolf - Doesn't work
Captain Falcon - Doesn't work
Pikachu - Doesn't work
Squirtle -Doesn't work
Ivysaur -Hits down 15% damage
Charizard - Hits out 10% damage
Lucario - Hits out 10% damage
Jigglypuff - Doesn't work
Marth - Hits out 10% damage
Ike - Hits out 10% damage
Ness - Hits behind 10% damage
Lucas - Doesn't work
Mr. Game and Watch - Hits down 15% damage
Snake - Hits out 10% damage
Sonic - Hits out 10% damage
Zero Suit Samus - Hits out 10% damage
Timing notes and other stuff -
Some of the green group can be spiked if you wait a small amount of time before executing the forward B. Examples are zero suit and luigi, I'm sure many others are possible as well.
Wario - If you do get an air release, you should just upsmash him
Meta Knight - You can DACUS his air release
Ice Climbers - Probably won't get many grab releases on these two
King dedede - Strict timing, has to be very precise
Charizard - Strict timing, has to be very precise
Sonic - Strict timing, has to be very precise
Mr. Game and Watch - I was using this in some friendlies today and depending on the timing I was able to get other outcomes as well, but hitting down is the most common. Waiting a bit seemed to net a hit out, and perfect timing I think gave me a hit behind. More testing to come soon on this one.
Grouping -
Red Group 18%
Mario
Donkey Kong
Toon Link
Ice Climber(s)
Kirby
Ivysaur
Mr. Game and Watch
Green Group 36%
Luigi
Peace
Yoshi
Zelda
Pit
R.O.B.
King Dedede
Charizard
Lucario
Marth
Ike
Snake
Sonic
Zero Suit Samus
Purple Group - 5%
Olimar
Ness
Grey Group - 41%
Bowser
Diddy Kong
Link
Sheik
Ganondorf
Wario
Samus
Meta Knight
Fox
Falco
Wolf
Captain Falcon
Pikachu
Squirtle
Jigglypuff
Lucas
**NOTE** These are merely who it hits and how. This does NOT mean they are inescapable by any means. Most of them seem to work as "combos" but I'm sure there are a few that can be air dodged or something. However, due to the nature of this attack, I would not be surprised if the opponent either didn't react fast enough and/or had no idea wolf could hit them from so far away. Honestly these should work most of the time in a real match.
I hope this information hasn't been posted already. I haven't seen it, but there's always that chance. If it hasn't that's great, and I hope you enjoy sweet spotting wolf's forward B as much as I do, cause it's my favourite part of wolf and ultimately why I took the time to test this stuff. Thanks for your time.
*EDIT added the DACUS to meta knight's air release in other infos