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.
Founder effect and population bottleneck are not necessarily examples of genetic drift. The common thing in all three is a resulting reduction in genetic diversity. Genetic drift is a change in allele frequencies due to process of random sampling to form a finite offspring population from parent population.