Puck is a very unique Shakespearean character. Puck's uniqueness stems from the fact that Shakespeare uses Puck to relay his own thoughts concerning the themes of A Midsummer Night's Dream. For this reason, we can say that Puck acts as the voice of Shakespeare. While no other character in other plays acts as the voice of Shakespeare, we can see similarities between the fairy Puck and the spirit Ariel in The Tempest.
Like Puck, Ariel is very devoted to his master although for different reasons. Puck is devoted to Oberon simply because he admires Oberon and enjoys serving as Oberon's court jester, as we see in Puck's line, "I am that merry wanderer of the night. / I jest to Oberon, and make him smile" (II.i.44-45). Ariel is devoted to Propsero because he is a magician who freed Ariel from a witch's curse. The evil witch Syrocax had Ariel imprisoned in a pine tree for twelves years for disobeying her orders, and Propsero freed Ariel from the prison. In their devotion to their masters, both Puck and Ariel willingly do their masters' bidding. We see Puck willingly do Oberon's bidding when he brings Oberon the magical flower and also enchants the Athenians with the flower as Oberon requests. We see Ariel doing his master's bidding when we see him carry through with many commands.
Another similarity is that, while Ariel is not as much of a wit as Puck, they both enjoy their fare share of mischief. We see Puck being both witty and mischievous when he proclaims that he would enjoy watching two men pursue the same woman as it would be absurd and anything absurd gives him a great deal of amusement, as we see in his lines:
Then will two at once woo one.
That must needs be sport alone;
And those things do best please me
That befall preposterously. (III.ii.119-122)
Since the word "preposterously" can be translated as "ridiculously," we can see that Puck is declaring that he greatly enjoys what is ridiculous or absurd.
We see Ariel likewise acting mischievously when he relays to Prospero that by playing a pipe he charmed drunken Caliban, Stephano, and Trinculo into following him and left them in the filthy pool beyond Prospero's cell, as we see in his lines, "At last I left them / I'th filthy-mantled pool beyond your cell" (IV.i.201-202).