Mutant 38 Backpack excels in alpine terrain with refined features and guide-tested durability
What Our Gearhead® Experts Are Saying:
"The Mutant 38 is my go-to alpine pack for everything from winter mountaineering to long alpine rock routes. It’s light but super tough, and it carries like a dream when I’ve got a rope, tools, and layers. I love how strippable it is—I can dial it down for summit pushes or beef it up for overnight missions."
For the steepest lines and harshest conditions, we count on the Osprey Mutant 38 Backpack to stay close, stay light, and stay strong. Developed with feedback from mountain guides and built to handle high-altitude, cold-weather abuse, this alpine pack blends load-carrying comfort with technical precision. Whether we’re climbing mixed lines or pushing toward a remote summit, the Mutant 38 moves with us and adapts to whatever the route throws our way.
Its narrow profile and glove-friendly features make it ideal for vertical terrain, and we love how strippable it becomes for ultralight summit pushes—shed the top lid, framesheet, helmet net, and hipbelt padding to go lean. Dual ToolLocks, ski and rope carry, and reinforced gear loops let us haul technical equipment with confidence. Now made with bluesign® approved NanoFly® and robic recycled fabrics, it’s more sustainable without compromising strength.
Details
- 38L alpine climbing pack built for mountaineering, ice, and mixed routes
- Removable top lid with zippered pocket and integrated FlapJacket
- Dual ToolLocks and rope compression system for technical gear carry
- Reinforced A-frame ski carry and daisy chain loops for modular attachment
- Three-point haul system supports vertical hauling and anchors
- Snowshed backpanel prevents ice and snow buildup
- Reverse-wrap hipbelt with dual gear loops and removable padding
- Helmet carry net with multi-position adjustment and stowaway pocket
- Item #OSPZ1P8
- Responsible Collection
- Recycled/Repurposed, bluesign® APPROVED
- Material
- recycled high tenacity nylon, DWR treatment
- Volume
- [S/M] 36L (2197 cu in), [M/L] 38L (2319cu in)
- Support/Suspension
- Atilon
- Waist Belt
- yes
- Access
- top
- Gear Loops
- yes
- Helmet Carry
- yes
- Dimensions
- [S/M] 10.24 x 11.81 x 24.8in, [M/L] 10.24 x 11.8 x 26.77in
- Activity
- trad climbing, ice climbing, mountaineering
- Manufacturer Warranty
- limited lifetime
Reviews
Q&A
What do you think about this product?
Overall Rating
5 based on 9 ratings
Review Summary
Customer Images
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Selecting an option will reload the available reviews on the pageJuly 31, 2025
Excellent Pack!
Great pack, very light and straps in all the right places. Some really nice features that I’ve not seen on packs before such as strap tidies to stop them flapping in wind.
Originally reviewed on osprey-emea
July 9, 2025
This is my goto bag
[This review was collected as part of a promotion.] This is my goto bag for mountaineering. It carries comfortably, even with heavy loads, and every pocket, strap and feature is exactly what I want. With the exception of adding a hip belt pocket for snacks. Just took it up Rainier last weekend. My one big complaint- the hip belt is not long enough! Ok for men maybe, but this lady needs just one more inch. I sometimes have bruises right where the belt ends. Please fix this Osprey, and you’ll have the perfect bag!
Originally reviewed on Osprey
April 2, 2025
Great winter sack
Nice simple design, has just about all the features you need without being over complex. Nice low weight too. Very pleased so far.
Originally reviewed on osprey-emea
February 9, 2025
Overall a very good pack,
Overall a very good pack, which I’ve used on several Scottish winter mountain days so far. This is my second Mutant 38 pack and I think that the first one may have a bit more capacity. Also, I prefer the helmet enclosure on the older pack as it has a zip rather than Velcro fastener. A good mountaineering sack which I would recommend. If more capacity is required the 52 litre version may be an option.
Originally reviewed on osprey-emea
December 14, 2024
New bag day!
Exactly as expected, brilliant. Bought this to replace my old Mutant 38 ( which was given to my eldest son). Super happy.
Originally reviewed on osprey-emea
October 4, 2024
Everything I had hoped for
[This review was collected as part of a promotion.] Everything I had hoped for and more! I have been a P/T rock and ice climbing guide for the past thirty years and was the fortunate owner of a Mutant 28 zip-top pack for 10+ years (used summer and winter). Unfortunately, this pack was stolen from the back of my car this past August, with my entire rock rack contained within it (grrr!). Given all the positive experiences I had over time with that pack, I decided to replace it with the updated and larger 38L current version. Though I have only used it twice during the past week, it far exceeded my expectations. It is light, sleek, simple, versatile, well-designed, and carries heavy & bulky loads with ease and comfort. It has everything I want and nothing more - just what anyone would want in a backpack!!
Originally reviewed on Osprey
September 2, 2024
Great climbing backpack, really comfortable when fully loaded
Really well thought out backpack, well featured, very comfortable. I particialulary like the addition of the helmet carry and the quick buckled side compression for rope carry.
Originally reviewed on osprey-emea
August 11, 2024
I bought this pack specially
[This review was collected as part of a promotion.] I bought this pack specially for winter Search and Rescue where I need to be light and fast but also have the ability to add or subtract elements easily depending on the situation. For example, I like the straps that can be taken off entirely or that could be used to strap on a pair of snowshoes or closed cell foam pad. I took it out for a 15 mile overnight to test it, carrying about 20 pounds with full food and water. I really liked the narrow profile and it rode very well. Adjustability was good, and I like the fairly robust buckles; they will be helpful this winter in gloves. I miss having any option for a water bottle sleeve built in on the outside, but for this pack's intended purposes, it makes sense not to have it. I'd also note that I tested a couple Osprey accessories with it including a waterproof phone case, and that attached conveniently to the shoulder strap. Overall a well designed climbing and versatile pack that will meet my Search and Rescue needs. It also appears to be a nice balance between good durability and lighter weight. Not the pack the average backpacker wants, but great for climbing, or other activities that may require some flexibility of use, it's a great pack.
Originally reviewed on Osprey
May 14, 2024
Excellent, well-designed multi-pitch pack
I recently purchased a Mutant 38 and love it. It is built with durable, yet light material, with reinforcements at key points. While it's not "ultralight" in its stock form, dropping the brain and rigid backplate brings it to a very respectable 26oz, which is pretty darn light! The fit is excellent for climbing (the hip belt rides above a harness) and there is a ton of flexibility for attachments. Most importantly to me, the pack compresses down on itself very well, so it doubles as a larger capacity haul-in pack, but then cinches up small on your back for multi-pitch climbs with light gear.
Originally reviewed on Osprey
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