First off, I would suggest getting rid of the lotus petals and adding in two more lands. 20 is a bit low, even considering your mana generating creatures.
As for creature suggestions, gravecrawler would work very well in a deck like this. If you have the money, vengevine can be worthwhile too. Aside from that, I would just work on getting rid of some of the weaker creatures and getting up to four copies each of the good stuff.
If you find yourself looking for more removal, abrupt decay and maelstrom pulse are good inclusions as well.
4x Lotleth Troll
3x Ghoultree
1x Jarad, Golgari Lich Lord
1x Hythonia the Cruel
2x Deathrite Shaman
3x Birds of Paradise
3x Dregmangler
2x Corpsejack Menace
2x Varolz, the Scar-Striped
3x Trestle Troll
2x Pahrika, God of Affiliction
4x Reaper of the Wilds
2x Putrefy
2x Lotus Petal
2x Elixir of Immortality
8x Swamp
8x Forest
2x Overgrown Tomb
2x Woodland Cemetery
Looking for Ideas to improve this deck...
Thank you
As for creature suggestions, gravecrawler would work very well in a deck like this. If you have the money, vengevine can be worthwhile too. Aside from that, I would just work on getting rid of some of the weaker creatures and getting up to four copies each of the good stuff.
If you find yourself looking for more removal, abrupt decay and maelstrom pulse are good inclusions as well.
I don't know if you really need Elixir of Immortality here.
I agree that the Petals should be 2 more lands.
Glissa, the Traitor
creakwood liege
pernicious deed
Nevinyrral's Disk
spiritmonger
unearth
regrowth
rancor
troll ascetic
Thrun, the Last Troll