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.
In the sentence "Tina and party are planning a surprise party for Mary," the conjunction is "and." It connects the subjects "Tina" and "party," indicating that both are involved in the planning of the surprise party.
It was my birthday and I got a surprise!
Surprise visit on your birthday is the correct grammer. This is the correct grammer for the birthday wish.
The type of conjunction used in the sentence is a coordinating conjunction. In this case, "and" is joining two independent clauses (Tina is planning a surprise party for Mary, and Patti is planning a surprise party for Mary).
They threw him a surprise party for his 35th birthday.
The cast of Birthday Surprise - 2014 includes: Tety Kalafati as Young Woman
The conjunction used in the sentence "Tina and Patti are planning a surprise party for Mary" is "and." It connects the two subjects, Tina and Patti, indicating that both are involved in the planning.
The conjunction used in the sentence is "and." It connects the two subjects, Tina and Patti, who are planning a surprise party for Mary.