As more underwater areas are being added to the server, maybe we could have the possibility of having special invasive plants seeds related to that theme as well? For instance, Kelp Forest, which would attract Kelp Creeps.
Maybe more rare and special and difficult seeds that would make raise shambling mounds and thornhusks to the area as well.
Also, in the theme of Magma and lava for the spreading of Magma Lizards and Fire Wasps.
And last, but not least, some ooze oriented theme to promote the spread of slimes and ooze, maybe? To slowly corrode rocks and walls with such creatures, making structures of the area to crumble with acid pools and the like?