I had no experience of using the verb "sneak", so I just followed the dictionary
sneak: 2 TAKE/GIVE SECRETLY [transitive] to hide something and take it somewhere or give it to someone secretly
I snuck her a note.
sneak something through/past etc somebody/something
Douglas had sneaked his camera into the show.
So, we can "give something to someone secretly"
I am not sure if this sentence is common or idiomatic "He sneaked the spider on his mom's shoes to freak her out"?
Some suggest "He sneakily put the spider on his mom's shoes to freak her out".
But which one is more natural?