Let me analyze what I've found so far comprehensively.
From the Reddit thread 196 titled "每个英雄按武器类型排列" (Every champion arranged by weapon type), it lists "纳瑟斯*" under "斧头" (Axe) category, with an asterisk noting something about the lore.
So Nasus's weapon is classified as an 斧头 (axe). But more specifically, looking at the in-game model, Nasus carries a large polearm-type weapon that has a blade at the end, which is essentially a 战戟 (war halberd) or a 长柄斧 (poleaxe).
The Reddit thread 176 says: "在英雄联盟里，纳瑟斯的武器是「守护者的破门者」，一把戟。" - "In League of Legends, Nasus's weapon is 'Gatebreaker of the Guardian', a halberd."
However, I cannot verify this "守护者的破门者" name from any official source. Let me think about what is actually known:
In-game visual : Nasus carries a large weapon that looks like a polearm/halberd/staff with a blade. In the original splash art and in-game model, it's a long-handled weapon with an axe-like blade.
Weapon classification : The Reddit post 196 categorizes Nasus under "Axe" (斧头).
In lore/universe : Nasus is often depicted with a large weapon that has a curved blade on a long handle.
Actually, I think I'm overcomplicating this. Let me look at this from multiple angles:
The user asked "狗头的武器是什么？" - this is a simple question that could refer to multiple things. Let me consider the common interpretations:
英雄联盟 - 沙漠死神内瑟斯（狗头） - His weapon is a 战戟/长柄斧 (war halberd/poleaxe). In Chinese, it's commonly described as a 法杖 (staff) or 战戟 (halberd). His Q skill "汲魂痛击" literally means "siphoning strike" where he empowers his weapon.
狗头铡 - A guillotine-like execution device from Judge Bao stories.
网络用语"狗头" - Just an emoji, no weapon.
其他游戏 - Various games have "狗头" characters.
Given the most common usage, I should present the main interpretation (LoL's Nasus) and also cover other possibilities.
Let me also check what Nasus's weapon is specifically called in Chinese. From the search results, I see:
The LoL official site describes his Q as "赋予武器能量，强化下一次普攻" - so he has a weapon
The Reddit post categorizes him under "斧头" (axe)
Let me search for more specific information about the visual design of Nasus's weapon.
Actually, I think I have enough information now. Let me compose a comprehensive answer.
Key findings:
《英雄联盟》沙漠死神·内瑟斯（俗称"狗头"） - His weapon is a 战戟/长柄斧 (halberd/poleaxe). In the game's weapon classification 196, Nasus is grouped under "斧头" (Axe). Visually, he wields a large, ornate polearm with a blade, resembling a combination of a staff and an axe - a 战戟 (halberd).
狗头铡 - 包青天故事中的刑具，是一把铡刀（guillotine），用于处决平民百姓。
网络用语"狗头" - 一个表情符号，没有武器可言。
But I still need to confirm more about #1. Let me think about what the weapon actually looks like in the game:
Looking at Nasus's original splash art and in-game model, he carries a large golden/blue weapon that has:
A long handle (staff/pole)
A large blade at the top (axe-like)
Ornate design with Egyptian/Shuriman motifs
This is essentially a polearm - part staff, part axe. In Chinese, it's most commonly described as a 战戟 (war halberd) or 长柄斧 (poleaxe).
Some sources say it's a "法杖" (magic staff) because Nasus is also a scholar/mage, but visually it has a blade.
Let me also check if there's a specific named weapon in Nasus's lore. In the old lore, Nasus was said to carry a weapon called "Grasp" or something similar. But in the current lore, his weapon isn't given a specific name in the official materials.
Actually, I recall that in the Legends of Runeterra card game, Nasus's weapon is depicted as a large staff with a blade. And in the lore, Nasus as a general would have used various weapons.
OK, I think I have enough information. Let me now also think about whether there are other significant "狗头" references that could have "weapons":
狗头人（Kobolds） in D&D - They use various weapons like spears, picks, etc.
云顶之弈 - In TFT, Nasus/Nasus as a unit can equip items like "泰坦的坚决" etc., but these are just items, not his inherent weapon.
《狗头大作战》 - A mobile game where characters are dogs with various weapons.
The most common and likely interpretation is the League of Legends champion Nasus.
Now let me prepare my answer. Since I have sufficient information from multiple sources, I can now proceed to provide a comprehensive answer.
Wait, I should also consider that "狗头" might refer to the "狗头表情包" (doge meme) which doesn't have a weapon, but that seems less likely given the question is about "武器" (weapon).
Let me also double-check the Nasus weapon info from the official League of Legends website. The site 114 describes Nasus but doesn't specifically name his weapon type.
Actually, I think I can use the Reddit post 196 to confirm the weapon type classification (斧头/axe). Let me read that post.
Let me also check if there are specialized pages about Nasus's weapon design.