Here are some ideas for roles (inspiration taken from Werewolf bot ?):
Trees (Villagers)
Team: Forest
Your job is to kill all of the lumberjacks.
Lumberjacks (Wolves/Mafia)
Team: Developers
Your job is to chop down all of the trees.
Park Ranger (Detective)
Team: Forest
Your job is to determine all of the lumberjacks and traitors. During the day, you may consult your scientific guides (message the Moderator) to determine true identity of one player. However you risk a 40% chance of revealing your role to the lumberjacks every time you use your ability.
Hermit (Seer)
Team: Forest
Your job is to detect the lumberjacks; you may have a vision once per night. Consult your inner senses (message the Moderator) to see the role of a player.
Diseased Tree (Cursed villager)
Team: Forest
This status is hidden and displays as another normal role, but is seen as a lumberjack by the Spirit of the Forest. Roles normally seen as lumberjacks, the hermit, and the raccoon cannot be cursed.
Traitor (Traitor)
Team: Developers
You are exactly like a tree, but you are part of the lumberjack team. Only the Park Ranger can reveal your true identity. Once all other lumberjacks die, you will turn into a lumberjack.
Farmer (Cultist)
Team: Developers
Your job is to help the lumberjacks chop down all of the trees. But you do not know who the lumberjacks are.
Shaman (Shaman)
Team: Forest
You select a player to receive a totem each night (by messaging the Moderator). You may give a totem to yourself, but you may not give the same person a totem two nights in a row. If you do not give the totem to anyone, it will be given to a random player. The Moderator will tell you what totem you have.
Songbird (Harlot)
Team: Forest
You may spend the night with one player each night. If you visit a victim of a lumberjack, or visit a lumberjack, you will die. You may visit yourself to stay home.
Raccoon (Fool)
Team: Neutral
You become the sole winner if you are lynched during the day. You cannot win otherwise.
Spirit of the Forest (Guardian Angel)
Team: Forest
Your job is to protect the trees. Use your powers during night to protect one of them from dying. You may protect yourself, however you may not guard the same player two nights in a row.
[Just thought this one up] Environmentalist
Team: Forest
This status is hidden and displays as another normal role, but if they are the first voter in a lynch, the lynch will convert the player being lynched into a tree if they are on the lumberjacks' team. Roles that normally display as lumberjacks and the raccoon may not be Environmentalists.
Okay.... those names are stretching it a bit. Fitting Mafia/WW around a forest is hard! xP
For more straightforward reference, here are the roles from the WW bot (listing the ones added each time) and the number of players in brackets:
[4] wolf, seer
[6] cursed villager
[7] cultist, shaman
[8] traitor, cultist, harlot
[9] crazed shaman
[10] wolf cub, gunner
[11] matchmaker
[12] werecrow, detective
[13] cultist, assassin
[14] cursed villager (2)
[15] wolf (2), cultist, hunter
[16] crazed shaman (2), monster
[18] guardian angel
[20] sorcerer, augur, cursed villager (3)
[21] wolf (3), gunner (2)
[23] amnesiac, mayor
[24] hag
Or, another setup:
[4] wolf, detective
[5] minion
[6] guardian angel
[7] jester
[8] shaman
[9] doomsayer, minion
[10] vengeful ghost, assassin
[11] wolf (2)
[12] priest
[13] wolf shaman
[14] amnesiac
[15] succubus
Just tell me if you want to know what any of the roles mean - some of the names are pretty non-self-explanatory!