Give him one of these. I own one and I love it.

It's especially nice for fishermen because it's got multiple little tools in it that are great for fishermen (Including a miniature flashlight for finding swallowed hooks and scissors for cutting line) and it's pretty durable and easy to clean.

• Ziplock bags
• Earplugs
• Paper napkins

And this is MUST for every traveler!

Here are some good options that I personally own:

• Black keychain: https://www.amazon.com/gp/product/B00004YVB3
• White keychain: https://www.amazon.com/gp/product/B000FNIKIQ
• All the bells and whistles: https://www.amazon.com/gp/product/B0009KF4GG/

Here are some other interesting designs:

• Card-shaped and can fit in a wallet (different color options): https://www.amazon.com/gp/product/B001Y7VR32/
• A floral print of the above, if he's the sort of guy who's into Hawaiian shirts: https://www.amazon.com/gp/product/B07PFWRPR9/
• A $23 design: https://www.amazon.com/dp/B00004YVB4
• The above, in black: https://www.amazon.com/dp/B0007QCOB0/
• Similar to above, but with a few more tools: https://www.amazon.com/dp/B000MLU8PE/
• A $24-80 design available in many different colors: https://www.amazon.com/dp/B0053G2AGS/
• $52, includes a nice pouch: https://www.amazon.com/dp/B000IOG3ZO/
• A $72 design: https://www.amazon.com/dp/B001B152LO/
• A $100 design: https://www.amazon.com/dp/B0007QCP50/
• A $105 design (blue): https://www.amazon.com/dp/B0007QCP64/
• A $115 design: https://www.amazon.com/dp/B000KFMTS6
• A $226 design: https://www.amazon.com/dp/B00006OALR/

Finally, these are some different mulitools:

• $105, comes with a nice pouch: https://www.amazon.com/dp/B0027MSC2M/
• $108, comes with a nice pouch: https://www.amazon.com/dp/B001ET6ACI/
• $133, comes with a nice pouch: https://www.amazon.com/dp/B001ET6ACS/
• $150, comes with a bunch of extras: https://www.amazon.com/dp/B000H3AL9A/
• $90-150, available in different configurations: https://www.amazon.com/dp/B000FNIL8K

The options are pretty overwhelming, lol.