It's a pre-Hardy Stan Laurel comedy short and a parody of Dr Jekyll and Mr Hyde. Mostly it's doing the 1920 John Barrymore film. Wikipedia thinks it's also referencing the 1912 film and the lesser-known of the two 1920 adaptations (i.e. the one with Sheldon Lewis), but don't ask me to tell you anything about those two.
Something I hadn't known about Stan Laurel is that before hitching up with Oliver Hardy in 1927, he went in for parodies. The one that always seems to get mentioned first is his version of Rudolph Valentino's Blood and Sand (1922), in which he played Rhubarb Vaselino and the title was Mud and Sand. It hit cinemas only three months after the original. This sounds like a lot of fun, but of course most people today are unlikely to have seen any of the originals he's parodying. I shouldn't think even the Barrymore Jekyll and Hyde gets much screen time these days and that's one of the classics. Other examples include turning West of the Pecos into West of Hot Dog (1924), Rupert of Hentzau into Rupert of Hee Haw (1924) and so on. Another one, Yes, Yes, Nanette (1925), is only directed by Laurel rather than having him as its star, but on the other hand its cast does include Oliver Hardy.
Anyway, this one's pretty good. The parody still works today because we all know the story, but furthermore the Barrymore version was so influential that even if you've never seen it you'll probably find yourself recognising Laurel's Mr Pryde anyway. It's quite something, actually. I wasn't sure if I was still looking at Stan Laurel. He's puffs out his face, pulls his head into his shoulders and dons a greasy black Beatle wig and some padding under his coat to make him bigger. This really works and he's immediately recognisable as Barrymore's Hyde. These scenes are easily the funniest in the movie, with Laurel's excited skipping whenever he's done something evil, e.g. using a peashooter or popping a paper bag. You have no idea. In this movie, the essence of wickedness is acting like a four-year-old. It's a simple gag, but very, very funny.
Laurel's Dr Pyckle is interesting too. He's funny as well, but it's a very different kind of humour. It's a performance you could do on TV today, whereas Pryde is much more physical. I laughed at his under-reaction to sitting in acid, for instance, although for some reason the film seems to think acid only burns away cloth and so the gag becomes about not showing nudity rather than not showing pain. It's an interesting performance that'll extend your opinion of Laurel as an actor, both in his own right and specifically as a take-off of Barrymore, but the script's just the usual slapstick, e.g. breaking bottles over his head, etc. It's also worth mentioning the tour-de-force sequence in which Laurel shows off the most extraordinary physical dexterity as the character he's playing loses all control of his legs. It's as if he's got drunk and discovered extra knees.
There's the odd Looney Tunes moment, with Laurel pulling a three-foot-long bottle from his coat and later wiping his face clean with a special effect. I'd also call Dr Pyckle's spectacles a mistake, although I understand why they're there.
Believe it or not, I actually found Laurel's Pyckle a little creepy. It seems more common for people to find Pryde the scary one, comparatively speaking, but I can imagine Pyckle as the spiritual cousin of Herbert West: Reanimator and other mad scientists.
It's a surprisingly lavish-looking production. The producer got access to Universal's sets and wardrobe department, so it looks like a proper period piece. You've got everyone running around in authentic Victorian costumes on some rather lovely sets, although the illusion of this being London is undermined by some French being written above an archway. Most of Laurel's 1920s parodies were apparently very low-budget, but this is an exception. Meanwhile his co-stars include a lovable dog called Pete the Dog who went on to do a staggering number of films and Julie Leonard, who's somehow not quite the blond bimbo you might expect and had done quite a few Stan Laurel films although she didn't work too long in Hollywood (1921-25). At one point Pete the Dog drinks some potion and becomes Evil Pete the Dog, which means that his behaviour is unchanged but he's wearing a bird's nest wig.
The intertitles are trying a little too hard. Here's the first one, for instance. "We squirm under the tumult of Good and Evil ever -- warring within us, yet were Science to separate them, Bad would flourish, Crime run riot. Even Saxophone players would be tolerated." That's pretty typical. They're all like that. They be funnier if you heard them spoken aloud as dialogue, I think, although they're not a bad bunch of gags.
The ending's a bit abrupt, though. It's enough to make me wonder if the film isn't missing some footage, since for years it was thought to be a lost film until some French prints turned up. What happens is as follows. Julie Leonard screams, the mob rush towards Dr Pyckle's house, Leonard breaks a bottle over Laurel's head and... the end! Eh? I'd wanted to see what Laurel would do next!
Is this worth twenty minutes of your time? Absolutely. I don't think there's any excuse for not watching it, to be honest. An evil hopping Stan Laurel is priceless, but it's arguably weirder to see his Dr Pyckle because we're not used to seeing him playing intelligence. Laurel in real life was clever and multi-talented, but the persona he played (extremely well) opposite Oliver Hardy for about twenty years was a half-witted man-child. The general consensus seems to be that Stan and Ollie's solo work before they teamed up wasn't as memorable as the stuff they did together, which doesn't seem surprising if one bears in mind that forgotten things tend to get forgotten for a reason, but this film is something a bit different from the usual run of things... and more importantly has some really funny bits.