Early in Filmation’s history, Scheimer also contributed a number of guest or secondary voices for the various productions. Amongst these was the voice of N’kima, Tarzan’s monkey companion in Tarzan, Lord of the Jungle (1976–81).  Scheimer played a significant role in the creation of the cartoon He-Man and the Masters of the Universe and Bravestarr. Aside from being the executive producer, he was also co-credited for the series’ musical score under the pseudonym “Erika Lane” (which combined the names of his daughter Erika and son Lane), and became a voice actor for the show (as he had done for many of his company’s previous productions), going under the pseudonym “Erik Gunden”. Scheimer’s contribution to the cast was in fact most notable as he voiced several supporting characters, including Orko (and other characters with a similar Smurfs-voice), Stratos, King Randor and others, due to severe budget restrictions. The animated series also pioneered a type of programming known as first-run syndication. Also a first was the storyline being based on an action figure toy; prior to this time, FCC regulations had prohibited any type of children’s programming being based on a toy. Scheimer transformed He-Man from a graphically violent version of Conan the Barbarian into a pro-social character, who imparted a life lesson to impressionable viewers in each episode.  Scheimer’s daughter, Erika, also did supporting female voices and occasional voice-acting for young boy characters. She would later star in the follow-up series She-Ra, which Scheimer also produced.

In the late 1990s, Scheimer returned to the field of animation. A Dutch investment company, Dreamweavers, NV., approached Lou with a concept based on an off-kilter Dutchman’s renderings of characters aimed at young adults. Scheimer went into production on an animated feature film entitled Robin and the Dreamweavers. Robin, the first human ever born in cyberspace, battled the evil siren “Triple XXX” who desired an earthly body and gained power through mankind’s baser carnal desires. The film, however, was never distributed.  Scheimer also provided consultation work for Gang of Seven (G7) Animation.  The Lou Scheimer Gallery at the ToonSeum, a museum of comic and cartoon art in Pittsburgh Pennsylvania, is named in his honor.

Scheimer voiced characters for other Filmation cartoons besides He-Man. Most notably, he provided the voice to “Dumb Donald” on the long-running Fat Albert and the Cosby Kids. He was also the voice of Legal Eagle and the Brown Hornet’s sidekick Stinger. He likewise served as the voice-over narrator during the opening credits of the majority of Filmation shows and cartoons. In Jason of Star Command and Space Academy, he was consistently heard as generic voices over intercoms. In the live-action series The Ghost Busters, which starred Forrest Tucker alongside Larry Storch with Bob Burns, his was the voice of “Zero”, the unseen boss of the main characters. Scheimer also provided the voices of Bat-Mite, the Bat-Computer and Clayface (First Appearance) on The New Adventures of Batman, a Filmation cartoon in 1977.

He was married to Jay Scheimer unitil her death in 2009; they had one daughter, Erika, and one son, Lane.  Scheimer underwent quadruple bypass surgery in the late 1990s and was subsequently diagnosed with Parkinson’s disease. He died from the disease at his home in Tarzana, California on October 17, 2013, two days shy of his 85th birthday.