You can choose Undertale characters and fight against others in multiplayer.. Undertale [Fight]

[@ThanosTheSans]

0 (Continue with the next number in the answers)

[@ThanosTheSans]

1

[@ThanosTheSans]

2

[@ThanosTheSans]

3

[@Darker_Death]

4 the Letters of Sans name

[@Darker_Death]

5 (need a Helping Hand?)

[@baimea4332]

You should play alternate battleground, fallen down, random battle place, or Undertale test play reborn. All of them are Undertale Battleground game and very recommended