Haylee has 3 x 12 = <<3*12=36>>36 guppies.
Jose has 36 / 2 = <<36/2=18>>18 guppies.
Charliz has 18 / 3 = <<18/3=6>>6 guppies.
Nicolai has 6 x 4 = <<6*4=24>>24 guppies.
Altogether, the four friends have 36 + 18 + 6 + 24 = <<36+18+6+24=84>>84 guppies.
#### 84