Frequently, cards that do things like this have that aspect or are large enough to explain why a target creature would acquire the abilities. Either via size (giants throwing critters) or as a ride.

This doesn't have either and that sticks out to me as odd.

I'd probably have done this as a 'one time a turn only' activation cost, rather than free on your turn.

But give it suitable art and I see no real problem with it as it is.

> As long as it's your turn, ~ gets +1/+1 and has flying.

Thanks. Sometimes I get the templating right, sometimes not so much.