When I'm chasing my baby around the room, I frequently tell him, "I'm gonna get you!" and catch him and tickle him. Is there a similar expression in Spanish? I'd love to find something that can be used everywhere, but regional answers are appreciated as well. It should express that we're playing, not that I'm going to get him because he's in trouble or anything.
In Argentina you would say
'¡Te voy a atrapar!' (prefered)
'¡Te voy a agarrar!'
I think 'Te voy a agarrar' makes it sound like he is in trouble, but not so much, you could still use it.
I would use some variant with
¡Que te pillo!
¡Te voy a pillar!
But I don't know about the neutrality of the verb "pillar" in other countries (I'm from Spain).
I would certainly use
coger too, but I know it is not "neutral" in many parts of America.
Some neutral expessions are:
¡Te voy a atrapar!
¡No te me escaparás!