Shrieking Drake

The return clause is mandatory, and that single word is the whole design. Most bounce creatures word the effect as "you may," giving you an opt-out when the board is empty or the trigger would set you back. Here there is no opt-out: when the Drake enters, you must return a creature you control to hand, with the creature chosen as the ability resolves. If it is the only creature on your side, the choice resolves onto itself and it goes straight back to your hand the moment the trigger resolves. Note the sequencing: it does enter the battlefield first (it has to, or there would be no trigger to put on the stack), then the resolving ability picks it up. That obligation is what keeps a one-mana flier with a free reset effect honest. It also flips the card's strategic axis depending on what you put in front of it. Point the return at a creature you actually want back (a tapped-out attacker you would rather protect, or a permanent whose entry effect is worth replaying) and the Drake is an enabler that resets that creature for a single blue. Aim it at an empty board and the Drake simply collects itself, costing you a mana to net no body. The 1/1 flier is the baseline rate; the obligatory return is the lever that decides whether the card is a value engine or a tax you pay to yourself.