Death mercilessly attacks the cripple. The cripple is missing one foot, but Death is missing both.
The text is from Todten-Capelle:
Ich bin wohl ein elender Krippel |
I may well be a miserable cripple |
A "triple" is presumably a "triple step" dance, where three steps are done on two main beats — as oposed to two-step.
The painting is somewhat more violent than the calm drawing in Todten-Capelle.
To find parallels, we can look at the dance in Basel (left), where Death is also missing one foot. It is not unusual for Death to imitate his victim, but it is a mockery to use a stick as a wooden leg.
With regard to the violence, we can look at the very Christian Sterbensspiegel (right), where a whole army of Deaths attack a group of beggars, but strangely enough, leaves Lazarus the beggar alone.