Mr. Sabry, a portly 67-year-old lawyer, is one of the most prolific litigators in a country where the law allows one citizen to press charges against another for vague crimes like immorality and “insulting” the nation. While it falls to a government prosecutor to decide whether to pursue such cases, and many are dismissed as frivolous, the successes have stifled free speech, hobbled the arts and even swayed national politics.

A tireless vigilante who wields the law like a cudgel to enforce his prickly, often paranoid, brand of Egyptian nationalism, Mr. Sabry claims to have filed more than 2,700 such public interest lawsuits in the past 40 years, often firing off several in a day. His legal darts have targeted actors, clerics, politicians and even belly dancers, and may play a decisive role in the next presidential election.

Many cases fizzle out. This was his third suit against the puppet show, which he previously sued for a skit on the novel “Fifty Shades of Grey.” A judge threw out that case.

When Mr. Sabry succeeds, however, the consequences can be far-reaching.

A clerical televangelist known as Sheikh Mizo, who irked Mr. Sabry with his teachings, was jailed for five years in February. Ahmed Naji, a writer, was thrown in jail for nine months in 2016 based on a complaint that Mr. Sabry supported. (The chief litigant, another lawyer, claimed that racy material in Mr. Naji’s novel had strained his heart.)

In November, Mr. Sabry helped get Sherine, a smoldering pop diva, banned from performing in Egypt after she had made a biting joke about the quality of the famously dirty water in the Nile.