What “Charlotte´s Web” did in the popular imagination for the humble, much-maligned barn spider, “My Octopus Teacher” sets out to achieve for the eight-limbed mollusc of its title – a creature of great, shimmery beauty and mystery regarded by many with more bemusement than affection. That´s a PR status that has kept hungry humans high on the octopus´ long list of enemies, but Pippa Ehrlich and James Reed´s engaging, massively crowdpleasing Netflix documentary goes out of its way to humanize these amorphous aliens of the sea: both through standard anthropomorphic techniques familiar from the nature-doc playbook of Attenborough and Disney alike, and through the empathetic presence of its producer-narrator, South African filmmaker and conservationist Craig Foster. Foster´s unexpected kinship with a single octopus, encountered while diving in the richly populated kelp forest of South Africa´s Cape of Storms, gives this simply framed doc its narrative thrust and emotional heft. Cynics might balk at the film´s aggressive manipulation of the heartstrings, but there´s little denying the combined effectiveness of its ravishingly filmed underwater observation and its unabashed but earnest psychological projection. A word-of-mouth phenomenon since its Netflix premiere in September, “My Octopus Teacher” is a surprisingly rare example of an international South African hit centered on the country´s richly diverse environmental tapestry: One can only expect a trail of comparable works in its wake. The bluff, affable Foster, for his part, has been working that beat for 20 years, since the release of his 2000 documentary “The Great Dance” – a survival study of the indigenous San people in the Kalahari Desert that netted some international distribution, but nothing like the exposure granted his latest credit. Handing the directorial reins to eco-journalist and first-time helmer Pippa Ehrlich and nature-doc pro James Reed, Foster settles into an unusual combined role of presenter and protagonist: somewhat indulgently so at the outset, as he talks viewers through a period of professional burnout he experienced some years ago, spurring a renewed urge to connect with the natural world. As Foster tells it, freediving in the local seaforest near his Cape Town home provided the therapeutic balm he was looking for; a surprising soul connection with a spirited octopus was an unplanned bonus. The polished construction of “My Octopus Teacher” suggests nothing quite so spontaneous. Iridescently shot by ace underwater specialist Roger Horrocks (responsible for some astonishing imagery in the BBC´s “Our Planet” and “Blue Planet II” series), the film´s extraordinary below-seascapes are clearly the outcome of painstaking study and exploration. The female octopus in question is but one attraction in a splashily filled coloring book of wafting kelp, electric-bright fish, knobbly crustaceans and darting, Beetlejuice-striped pajama sharks – a consistent threat to our tentacled friend, and the reason we first encounter her in a state of camouflage, clenched and covered in a makeshift cloak of shells to escape the predator´s notice. This is the first of several canny survival strategies that Foster narrates in order to sell us on the octopus´ remarkable humanoid intelligence and occasional sense of play. We also observe her crafty sneak-attacks on her own prey, her seemingly whimsical taunting of passing shoals of fish, and further outwitting of those sharks, whose villainous edit here (complete with tense, zithery music cues) may be rather unfair in the grand circle-of-life scheme of things, but fits the film´s tidy, family-friendly storytelling. After all, the sharks aren´t the ones apparently bonding with Foster himself, while his gradual buildup of trust with his octopus subject, culminating in tender scenes of hand-to-sucker contact, leaves us duly misty-eyed. If the science here is less than rock-solid, that´s somewhat beside the point. The documentary captivates as a vision of an earthy parallel universe, into which Foster´s platonic octo-romance is a moving audience conduit; above all else, as a couple of closing titles make clear, “My Octopus Teacher” is a bang-up PSA for the conservation work done by Foster´s nonprofit Sea Change Trust. It would achieve all this, however, without its most strained attempts at so-like-us association between its two principals, as Foster weaves his own arc of personal catharsis around our underwater hero´s short life cycle: By the time he claims to feel “a kind of dismemberment” when the octopus loses a limb to a snapping predator, it´s tempting to say the conceit has itself, well, jumped the shark. Still, “My Octopus Teacher” never loses our goodwill: If we wind up wishing it had a little less man and a little more beast, that only serves its cause.