Because this person whom you wish to phone is a friend of yours, there is an excellent chance that he will recognize your voice, hence, you will not be anonymous. You could also disguise your voice, but people speaking in a disguised voice usually sound weird, and it can be obvious that the voice has been altered.
I am not sure what kind of prank you had in mind. I think the usual idea is, you can make someone feel worried, and then you can make them feel relieved, when they discover that what they were worried about is actually a joke. This is rarely as much fun to experience as you may think.
Perhaps you should phone him up to tell him that for his birthday this year, you will be sending him a live, fully grown elephant. Of course, chances are he won't believe you. For extra laughs, actually send him an elephant.
Maybe they are planning a surprise birthday party for you and are "throwing you off the scent"
Perhaps they're planning a birthday surprise for you and they don't want you to find out what they're doing yet.
She's finding it difficult to be secretive about planning her husband's surprise birthday party.
The nouns in the sentence are party and challenge. The word planning is a gerund, a verbal noun.
Surprise visit on your birthday is the correct grammer. This is the correct grammer for the birthday wish.
Droughts in Australia are never a surprise. As the second driest continent in the world, Australia is subject to frequent droughts, and it is probably more of a surprise when there isn't a drought.
It was my birthday and I got a surprise!
They threw him a surprise party for his 35th birthday.
The cast of Birthday Surprise - 2014 includes: Tety Kalafati as Young Woman
Yes, the word 'surprise' is both a verb (surprise, surprises, surprising, surprised) and a noun (surprise, surprises).Examples:We're going to surprise Jack on his birthday. (verb)It will be a surprise, he won't be expecting it. (noun)
LazyTown - 2004 Birthday Surprise 2-16 is rated/received certificates of: Australia:G
Surprise is typically expressed through exclamations or sudden reactions that convey shock, astonishment, or disbelief. It often includes elements of unexpectedness and can manifest in various forms, such as gasping, shouting, or jumping.