diff --git a/crates/engine/src/catalog.rs b/crates/engine/src/catalog.rs
index da8100fef..3b3101f1e 100644
--- a/crates/engine/src/catalog.rs
+++ b/crates/engine/src/catalog.rs
@@ -210,6 +210,7 @@ pub static TOOL_GROUPS: &[ToolGroup] = &[
                     item("Highlight text", "highlighter", "comment.highlight", Ready),
                     item("Underline", "underline", "comment.underline", Ready),
                     item("Strikethrough", "strikethrough", "comment.strikeout", Ready),
+                    item("Squiggly underline", "spline", "comment.squiggly", Ready),
                     item("Text box", "type", "comment.freetext", Ready),
                 ],
             },
diff --git a/crates/engine/src/commands.rs b/crates/engine/src/commands.rs
index 2862d5eb1..e22f2be5b 100644
--- a/crates/engine/src/commands.rs
+++ b/crates/engine/src/commands.rs
@@ -178,6 +178,7 @@ pub const COMMANDS: &[CommandSpec] = &[
     c("comment.highlight", "Highlight text", None, None, Annotate, "highlighter"),
     c("comment.underline", "Underline text", None, None, Annotate, "underline"),
     c("comment.strikeout", "Strikethrough text", None, None, Annotate, "strikethrough"),
+    c("comment.squiggly", "Squiggly underline text", None, None, Annotate, "spline"),
     c("comment.ink", "Draw freehand", None, None, Annotate, "pencil"),
     c("comment.line", "Draw a line", None, None, Annotate, "minus"),
     c("comment.arrow", "Draw an arrow", None, None, Annotate, "move-right"),
diff --git a/crates/ui-egui/src/comments.rs b/crates/ui-egui/src/comments.rs
index a51ff52b7..20ea284ee 100644
--- a/crates/ui-egui/src/comments.rs
+++ b/crates/ui-egui/src/comments.rs
@@ -30,6 +30,7 @@ pub enum CommentTool {
     Highlight,
     Underline,
     StrikeOut,
+    Squiggly,
     Ink,
     Line,
     Arrow,
@@ -48,7 +49,7 @@ pub enum CommentTool {
 /// The quick-bar flyout groups, in Acrobat's order: Comment ▸, Highlight ▸, Draw ▸.
 pub const GROUPS: [&[CommentTool]; 3] = [
     &[CommentTool::Note, CommentTool::TextBox, CommentTool::Callout, CommentTool::Attach],
-    &[CommentTool::Highlight, CommentTool::Underline, CommentTool::StrikeOut, CommentTool::Caret, CommentTool::ReplaceText],
+    &[CommentTool::Highlight, CommentTool::Underline, CommentTool::StrikeOut, CommentTool::Squiggly, CommentTool::Caret, CommentTool::ReplaceText],
     &[
         CommentTool::Ink,
         CommentTool::Line,
@@ -62,7 +63,7 @@ pub const GROUPS: [&[CommentTool]; 3] = [
     ],
 ];
 
-pub const ALL: [CommentTool; 18] = [
+pub const ALL: [CommentTool; 19] = [
     CommentTool::Eraser,
     CommentTool::ReplaceText,
     CommentTool::Attach,
@@ -76,6 +77,7 @@ pub const ALL: [CommentTool; 18] = [
     CommentTool::Highlight,
     CommentTool::Underline,
     CommentTool::StrikeOut,
+    CommentTool::Squiggly,
     CommentTool::Ink,
     CommentTool::Line,
     CommentTool::Arrow,
@@ -91,6 +93,7 @@ impl CommentTool {
             Self::Highlight => "comment.highlight",
             Self::Underline => "comment.underline",
             Self::StrikeOut => "comment.strikeout",
+            Self::Squiggly => "comment.squiggly",
             Self::Ink => "comment.ink",
             Self::Line => "comment.line",
             Self::Arrow => "comment.arrow",
@@ -118,6 +121,7 @@ impl CommentTool {
             Self::Highlight => "Highlight",
             Self::Underline => "Underline",
             Self::StrikeOut => "Strikethrough",
+            Self::Squiggly => "Squiggly underline",
             Self::Ink => "Draw",
             Self::Line => "Line",
             Self::Arrow => "Arrow",
@@ -141,6 +145,7 @@ impl CommentTool {
             Self::Highlight => "highlighter",
             Self::Underline => "underline",
             Self::StrikeOut => "strikethrough",
+            Self::Squiggly => "spline",
             Self::Ink => "pencil",
             Self::Line => "minus",
             Self::Arrow => "move-right",
@@ -166,6 +171,7 @@ impl CommentTool {
             Self::Highlight => Some(Markup::Highlight),
             Self::Underline => Some(Markup::Underline),
             Self::StrikeOut => Some(Markup::StrikeOut),
+            Self::Squiggly => Some(Markup::Squiggly),
             _ => None,
         }
     }
@@ -190,7 +196,7 @@ impl CommentTool {
         match self {
             Self::Note => Shape::Note { at: [0.0; 2], icon: NoteIcon::Comment },
             Self::TextBox => Shape::TextBox { rect: [0.0; 4], font_size: 12.0 },
-            Self::Highlight | Self::Underline | Self::StrikeOut => {
+            Self::Highlight | Self::Underline | Self::StrikeOut | Self::Squiggly => {
                 Shape::TextMarkup { kind: self.markup().unwrap_or(Markup::Highlight), quads: Vec::new() }
             }
             Self::Ink => Shape::Ink { strokes: Vec::new() },
@@ -286,6 +292,7 @@ pub fn tool_for(a: &Annotation) -> Option<CommentTool> {
         ("Highlight", _) => CommentTool::Highlight,
         ("Underline", _) => CommentTool::Underline,
         ("StrikeOut", _) => CommentTool::StrikeOut,
+        ("Squiggly", _) => CommentTool::Squiggly,
         ("Ink", _) => CommentTool::Ink,
         ("Line", _) => CommentTool::Line,
         ("Square", _) => CommentTool::Rectangle,
diff --git a/crates/ui-egui/tests/comments.rs b/crates/ui-egui/tests/comments.rs
index 1fafe9a50..499f7840c 100644
--- a/crates/ui-egui/tests/comments.rs
+++ b/crates/ui-egui/tests/comments.rs
@@ -554,3 +554,17 @@ fn hovering_a_comment_shows_its_author_and_text() {
     h.get_by_label_contains("Check this figure");
     h.get_by_label_contains("Ada");
 }
+
+#[test]
+fn the_squiggly_tool_marks_selected_text() {
+    let mut h = harness(|_| {});
+    h.state_mut().views[0].select_text(0, 4, 8);
+    assert!(h.state_mut().execute("comment.squiggly"));
+    h.run_steps(2);
+    let c = comments(&h);
+    assert_eq!(c.len(), 1, "{c:?}");
+    assert_eq!((c[0].subtype.as_str(), c[0].quads.len()), ("Squiggly", 1));
+    // It sits with the other text markup in the Highlight ▸ flyout, and edits as itself.
+    assert!(printcraft_ui_egui::comments::GROUPS[1].contains(&printcraft_ui_egui::comments::CommentTool::Squiggly));
+    assert_eq!(printcraft_ui_egui::comments::tool_for(&c[0]), Some(printcraft_ui_egui::comments::CommentTool::Squiggly));
+}
diff --git a/parity/acrobat-features.toml b/parity/acrobat-features.toml
index 314e35322..9cf0b43e4 100644
--- a/parity/acrobat-features.toml
+++ b/parity/acrobat-features.toml
@@ -3515,11 +3515,11 @@ title = "Squiggly underline"
 area = "E"
 tier = "P2"
 milestone = "M5"
-status = "partial"
-commands = []
+status = "shipped"
+commands = ["comment.squiggly"]
 tools = ["comment_add"]
-evidence = ["crates/annot/src/tests.rs::every_tool_creates_a_drawable_comment"]
-notes = "engine and agent tool; no toolbar entry yet"
+evidence = ["crates/annot/src/tests.rs::every_tool_creates_a_drawable_comment", "crates/ui-egui/tests/comments.rs::the_squiggly_tool_marks_selected_text"]
+notes = "Highlight ▸ Squiggly underline (with Underline and Strikethrough), the agent tool and the engine"
 
 [[feature]]
 id = "comment.replace-text"