Purpose. The article considers “virtual flashmob” (on the basis of comments to an English post) as one of the communicative forms of network folklore in order to describe its functions and forms of manifestation as well as to give a classification of the comments into thematic groups and analyze their linguistic peculiarities. Сomments of active users of the social network Instagram constitute the empirical base of this study. The theoretical base relies on works of Russian and foreign researchers of virtual folklore Nathan Chandler, Simon J. Bronner, Trevor J. Blank, V.P. Rukomoinikova, Yu.M. Sokolov, A.S. Kargin, etc. Methodology. The basis of the research is the methods of observation and description, as well as the structural-semantic and interpretative analyzing with the pragmalinguistic analysis. Results. The novelty of this work lies in the fact that it presents an analysis of the latest linguistic phenomenon, i.e. “virtual flashmob”, in the social network Instagram. The authors have developed a thematic classification of comments to an English post. The language of comments is analyzed from the point of view of folklore features. A number of precedent phenomena are considered. The place of comments in the general typology of network folklore is singled out based on the authors’ earlier research. Having analyzed the comments, we come to the conclusion that from the point of view of folklore features, the language of comments is bright, accurate and colorful. It precisely conveys the emotions of the discussion participants. Lexical repetitions, metaphors, colorful epithets, certain folklore formulas, proverbs, sayings, chants, epics, humorous inclusions, irony, anthropomorphization, etc. make virtual folklore so interesting and rich. There are examples of each type of comments presented in the thematic classification. An extended functional classification of comments is also developed. Gagachat is a striking example of the manifestation of folk art, which reflects cultural-forming factors such as news and pop culture. It contains some basic patterns characteristic of expressive communication both oral and virtual. Practical implications. The results of the study can be applied in the sphere of socio-political planning and forecasting as well as in conducting linguistic studies.