Felt crafts are great to do with Otters. You can pre-cut the felt shaped according to the templates below and have the kids glue them together. This can also be done as a virtual meeting over zoom if you get everyone the materials ahead of time.
Nicole with the 141st Irregulars in Florida created this Felt Otter Buddies Template. You will need a few different appropriate colors of felt (various shades of brown, tan, and white), googly eyes, a black sharpie, and glue.
Liz with the 22nd Wildwood in Oregon created this Otter Mask Template. You will need a few different colors of felt (similar to the otter buddies above), glue, and elastic. If you want them to be sturdier, you could also bring a needle and thread to stitch the elastic to the felt.