It's #EnigMarch, and when challenged to design a puzzle, I make time even if I feel kinda buried.
In this crossword, most clues are cryptic, but the clues that just say undead don't have any wordplay going on or anything; you just need to figure out some undead thingy you could inter in there.
When you've filled in the grid, the circled letters spell a word you might use to describe a crypt.
Across:
1. Baking soda, e.g., sounds like a musical instrument
4. Backwards graphic format, illus.
6. Seek prey like a stem (long)
8. Thorin, for example, is no ol' tossed Waldorf
10. Earlier, a game with black and white stones
11. Hat: a thing on which to wipe one's shoes backwards
12. Sounds like one of the Pep Boys cut grass
14. Consume brewed tea
16. Cincinanati Reds contain anger
18. Rob, headless, self-satisfied
19. Undead
23. Shelter is model train scale put into service
24. Rear of ship is young newt, afore
25. Sounds like a wildebeest again
Down:
1. Blue ad's not good
2. Spain without last resort
3. Mess up eastern railroad
4. Fire is fame around loss
5. Undead
7. Initially on friendly terms, often of poets
9. Confused, like Horton heard one
12. Italian mom is master of arts (mixed martial arts)
13. Undead
15. Equip with weapons an endless army
17. Owe ten shifted bird with bill
20. Marcus Aurelius holds modern empire
21. Headless agreement: dead ones tell no tales
22. Tree sounds like you
Rot13'd answers and an upside-down answer grid (not rot13'd):
Npebff: 1. Onfr, 4. Svt, 6. Cebjy, 8. Qjnes, 10. Ntb, 11. Gnz, 12. Zbj, 14. Rng, 16. Ver, 18. Zht, 19. Zhzzl, 23. Ubhfr, 24. Nsg, 25. Narj.
Qbja: 1. Onq, 2. Fcn, 3. Ree, 4. Synzr, 5. Tubfg, 7. Bsg, 9. Jub, 12. Znzzn, 13. Jvtug, 15. Nez, 17. Rzh, 20. HFN, 21. Zra, 22. Lrj.
Gur pvepyrq yrggref fcryy TEVZ
