At ages 78 and 86, Sid and Marty Krofft are enjoying an unlikely comeback. Maybe flashback is a better word: The brothers made their mark in the late 1960s by bringing a psychedelic sensibility to Saturday morning children’s TV. After they were hired in 1967 to create human-sized animal costumes for the flower-power-influenced “The Banana Splits Adventure Hour,” they launched their own production empire with trippy kids’ shows. They included “H.R. Pufnstuf” in 1969, “Sigmund and the Sea Monsters” in 1973, and “Land of the Lost” in 1974.

Over the years, they’ve been on the verge of reviving these and other properties many times (a 2009 “Land of the Lost” movie starring Will Ferrell didn’t do well.) Now they have three shows going at once, including a new “Sigmund and the Sea Monsters” series, whose pilot premieres June 17 on Amazon Prime Video. The original Sigmund, a shy monster whose family thought he wasn’t scary enough, was played by 3-foot-9 actor Billy Barty in a spongy green suit.

The Kroffts also launched a reboot of “Electra Woman and Dyna Girl” in April on the Fullscreen streaming service; it’s headed to iTunes in June. And their preschool program “Mutt and Stuff,” featuring puppets and puppies, has been on cable’s Nick Jr. since last July. It was nominated for two daytime Emmys. The brothers recently talked about their revival and a showbiz career which began when Sid assembled elaborate puppet shows in the 1950s, becoming a nightclub opening act for performers like Judy Garland and Liberace. Edited from an interview.

Is Sigmund still a little guy in a suit?

Sid: Yeah, but the suits are amazing.