The worst was an open source project I tried to look at.

It was written in Turbo Pascal.

I am not sure, never really got so far, but it looked like it was one single class with hundreds of methods and hundreds of instance fields for data.

Almost no data objects, if it needed for example 4 sets of 6 variables it had 24 instance fields and in some instances 4 different sets of methods for accessing said variables.

Around there I stopped looking ;)