You should have as many Troll Tokens as you have Trolls. Store them in your Imp Den.

One or more Troll Tokens can be used in any First Year room, including the Magic Room. Each token replaces one imp. (Two Trolls in a Magic Room produce a regular imp, not another Troll Token. Don’t ask us how they do that; it’s just magic.)

Troll Tokens cannot be used to Mine Gold or Dig Tunnels (however, they can produce gold or tunnels in the appropriate room) and do not count as imps for any other purposes (final scoring, Kamikaze Imp trap, Fist of Justice spell, Desertion event, etc.).