help me identify

[Wom001]

buying a mature 120gal tank and its been kinda neglected it has a huge colony of aptasia and some sea lice buggers but those can be delt with accordingly. there is somethign in the tank i cant identfy though its like a giant green cluster of like filaments or something idk iv never seen it but here are some pics of it hopefully ill be able toget closer ones soon, anyway any insight would be appreciated
pic 1.JPG

[TaTeR ToT]

Looks kind if like gsp

[Wom001]

yea but instead of wavy and like soft it looks pretty rigid the dude called it a nest of hook worms