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