Cattail is an Earth Pony living in Hayseed Swamp, and is the only known descendent of Mage Meadowbrook.
History
Trying to find a cure for Zecora and Steven Universe's Swamp Fever, Jasper, Peridot, Fluttershy and Starlight Glimmer arrive in Hayseed Swamp, soon finding Cattail inside Mage Meadowbrook's home. Upon learning of their situation, Cattail grants them access to Meadowbrook's old medical journals.
He gives his support throughout their stay,