Hi and welcome!
You can knit ears by casting on an odd number of stitches, knitting a couple of rows and then binding off a stitch at the beginning of each row until you have one stitch left. Pull the yarn tail through and you have an ear. I don't think it'll take very many stitches, depending on how large you want the ears.
There are some similar ideas on Ravelry (free to join) and some patterns for
bat hats as well.