Mardi Gras-a carnival held in some countries on Shrove Tuesday (the last day before Lent) but especially in New Orleans.
Bottleneck effect is when there's something that either kills the majority of the population or just prevents it from reproducing. This creates genetic drift because the likelihood of gene prominence changing is much higher in a small population. The Founder Effect is a type of Bottleneck effect. It is when a small amount of individuals starts a population usually due to migration.
The Founder and Bottleneck effect are both examples of Genetic drift as you mention. The end result is pretty much the same, i.e., a reduction in the genetic diversity of the population. The main difference is the cause underlying the drift. Say there's a very colorful ethnically rich and all population.